Ryatroxos (Ree-Uh-Trock-Os) is an extremely powerful ED-level Fanged Wyvern that first appears in Monster Hunter: Evolution.

Ryatroxos artwork by EmilyStepp
Titles Terrible King of Drakes
Nicknames Rya, Ryatrox
General Info
Species Fanged Wyvern
Habitats Scorched Plateau, Primeval Coastline, Forgotten Valley, Frozen Wilds, Elders Recess, Rotten Vale, Coral Highlands, Wildspire Waste and Ancient Forest.
Size 2923.5cm (95ft) Largest

1606.18cm (52ft) Smallest

Relatives Charred Ryatroxos, Anatroxos, Magnatroxos
Signature Move Corrosion wave
Elements Element Fire Fire
Ailments Status Corrosion Severe Corrosion
Status Bleeding Bleeding
Severe Fireblight Severe Fireblight
Status Stun Stun
Weaknesses Element Water
Creator Nrex117


​Ryatroxos is a large and powerful, quadrupedal Fanged Wyvern characterized by their crests, tusked lower jaws and well developed forelegs and hindlegs. Its thick hide is littered with hard boney osteoderms and shells as well as long acid filled spines along its back and tail which provide Ryatroxos with protection. Ryatroxos has a narrow and notched upper jaw filled with rows of razor sharp teeth and fangs. Like some snakes it has the ability to make its lower jaw wider to aid in swallowing large chunks of meat. It has four powerful legs with large claws like most other Fanged Wyverns, but it is able to use its forelegs as arms unlike other fanged wyverns. All of its four limbs have three walking digits with thick and powerful talons and pseudo thumbs to help grip objects and aid in bearing weight. Ryatroxos tail is very long and is adorned with powerful stinger like tail club filled with a highly concentrated form of its corrosive venom.


When not engaged in battle Ryatroxos can be seen wandering its territory in search of intruders, if it catches a scent or sight of an intruder, be it hunter or rival monster, it will proceed to attack its foe. Ryatroxos are relentless and aggressive predators. Ryatroxos are super-predators and are able to take the territory of other monsters with ease but unlike other powerful Monsters like Deviljho, Ryatroxos is not nomadic and tends to stick in an territory as long as it can. Ryatroxos is known to have 2 enraged states one state of minor rage where its spikes overproduce the acidic toxin causing it to leek acidic gas and a pure rage state where Ryatroxos normally dormant fire sack activates causing flames to surge across its body.

​Ecological Information

Placement In Food Chain

Ryatroxos is a large and powerful apex predator that is easily able to assert itself as top predator in practically all the environments it inhabits.

Behavior Towards Other Monsters

Ryatroxos are highly territorial predators and are known to actively hunt and kill other predatory species that trespass on its territory whether they are large or small. Herbivorous creatures are normally left alone unless they are territorial or if the Ryatroxos is hungry.


Ryatroxos are known to commonly leave footprints and is also known to mark its territory with its corrosive venom and scars left on the terrain with its jagged spines.

Specific Locale Interactions

Ryatroxos doesn't have any locale specific interactions.

Special Behaviors

Ryatroxos doesn't have any special behaviors.


Introduction Cutscene

  • Location: Wildspire Waste, Day
  • Synopsis: The Hunter has just entered the area and walks towards the edge of the cliff looking down on a small herd of seemingly distressed Apceros, the hunter is perplexed by what could be causing the armored and normally aggressive herbivores to panicking in such a manner. The hunter then realizes all the Apceros have focused their attention slightly above his/her general direction, the hunter then hears a deep growl and slowly looks back and up. The hunter freezes as they see a massive Fanged Wyvern perched just on the ledge above them, the titanic Fanged Wyvern lets out a deafening roar and leaps towards the Apceros herd and unknowingly towards the hunter. The hunter quickly jumps out of the way as the large Fanged Wyvern crashes into the ground and causes the Apceros herd to flee in terror. The Fanged Wyvern quickly resumes chase of the herd but is stopped by the bull of the herd who attempts to deter the Fanged Wyvern. The Fanged Wyvern quickly attacks the bull Apceros with its jaws only for its teeth to slide off its thick shell. The Apceros bull quickly retaliates with a blow from its tail to the Fanged Wyverns head, which did little but annoy the beast. The view returns to the hunter still lying on the ground watching the Fanged Wyvern effortlessly flip the Apceros bull over and deliver a lethal bite to its head and neck. The wyvern begins to feed as the hunter starts to rise and accidentally step on a dry branch alerting their presence to the large monster. The Beast slowly lifts its head and smells the air and then suddenly turns toward the hunter. The hunter prepares to defend themselves and the Monster growls, the hunt begins.


​As a quadrupedal Fanged Wyvern, its arms have evolved into forelegs, which allow it to move at great speeds with excellent mobility. Though its forelegs are developed to bear its weight it still has strong enough digits and claws to use as weapons. Ryatroxos hindlimbs are strong enough to bear all the weight of its body for extended periods of time allowing it to stand on them without the support of its stronger forelegs. Ryatroxos has a powerful set of jaws that are filled with multiple teeth and corrosive venom producing organs. As well as heat producing organs that can ignite the acidic toxin to create striking green flames when enraged.  

Rage and Tired States





In Game Information

Ryatroxos Icon.2 by Nrex117
Ryatroxos is a unusual and large theropod like Fanged Wyvern known for their thick scaly hide, powerful tooth filled jaws and corrosive venom. Among some of the largest Fanged Wyverns found thus far and with a temperament and ferocity to rival a Rajang! If this monster had wings it would easily have been classified as an Elder Dragon!


  • ​Order: Pseudosuchian
  • Suborder: Beast Foot Wyverns
  • Infraorder: Theropod Fang Wyvern
  • Superfamily: Death Jaw Wyverns
  • Family: Ryatroxos

Ryatroxos is a uniquely evolved member of the Fanged Wyvern classification which includes monsters like Zinogre and Odogaron, but seems to have some traits more in common with Brute Wyverns.

Habitat Range

​Ryatroxos is a highly adaptable monster and is known to inhabit most of the areas in the new world. Because of its highly territorial nature, Ryatroxos are difficult to observe but most specimens have been spotted in warm and tropical areas such as swamps, jungles and deserts and some have even been know to inhabit volcanic areas but is it assumed they can live in most other areas as well.

Ecological Niche

Ryatroxos is an incredibly powerful apex predator that is high on the food chain. Ryatroxos can easily prey on monsters such as Aptonoth, Larinoth, Bulldrome, Velocidrome and even other large monsters such as Yian Kut Ku and Congalala. Ryatroxos are also some of the few natural predators of the gargantuan Validoth. Despite being an apex predator, Ryatroxos has to compete with other large predatory monsters. Monsters like Zinogre, Tigrex, Rathalos and Rathian are potential threats to young or sick Ryatroxos. And despite having many predators to deal with Ryatroxos are quite deadly themselves with their corrosive venom and brute strength making them more than a match for such competition. Ryatroxos and Rajang are known to compete for some of the same rare resources which makes the two creatures fierce ecological rivals.

Biological Adaptations

Ryatroxos most unique feature is its jaws which are able to unhinge to aid in swallowing smaller prey whole and tearing larger chunks out of large prey similar to the jaws of a snake. Another feature Ryatroxos shares with snakes are heat sensing pits at the end of its snout that it uses to help track prey. Another unique feature Ryatroxos posses are its well developed for limbs that even have a pseudo-thumb and large thick claws used for grappling and wrestling other monsters to the ground. Ryatroxos also posses a unique venom that is highly toxic and corrosive, this venom is used to weaken and soften up its prey when it bites allowing for chunks to be easier to rip off and swallow. Ryatroxos can also use its acidic venom for self defense and can spit it as a projectile that explodes on contact or be left to detonate, stream or even a mist. Despite its large size it is quite agile and can move at high speeds and even jump and pounce onto prey.


Ryatroxos are relentless, aggressive predators with surprising skills in battle. These skills have made hunters consider them to be one of the most intelligent and powerful Fanged Wyverns. Their territories are marked with singe marks from their corrosive venom. These monsters are mainly active during the day thus making them diurnal. While adults Ryatroxos live a mostly solitary life, the young hatch lings are known to wonder away from the mothers nest in gangs to hunt on their own from time to time.



Flamethrower - Ryatroxos sucks in air and fires out a stream of fire akin to that of Teostra, dealing high damage and inflicting fireblight.

Dirty Trick - Ryatroxos uses its powerful arms to fling dirt and rocks in the direction of the hunter dealing low damage and inflicting stun.

Charge - A simple charging attack where it runs towards the hunters in hopes of trampling them, can quickly turn when preforming this attack. This attack is done in a similar manner to a Tigrex or Akantor charge.

Shoulder Slam - Ryatroxos lunges towards hunters in an attempt to hit them with its shoulders in a similar manner to Zinogre, this attack can inflict stun.

Bite - A simple bite that deals moderate damage to a hunter, this attack can inflict bleed.

Acid Projectile - Ryatroxos will fire a projectile of acid at a hunter dealing moderate damage and inflicts corrosion.

Acid Stream - Ryatroxos spits out a concentrated stream of acidic venom causing acidic gas to linger in the areas of impact this attack deals moderate damage and inflicts corrosion.

Rear Kick - Ryatroxos kicks backwards towards anything standing behind it with either one of its hind legs dealing moderate damage.

360 Acid Mist - Ryatroxos will spin in a circle spreading its acidic mist from its tail and jaws.

Frontal Stomp - Ryatroxos quickly slams the ground with it arms and claws dealing heavy damage to anyone caught in the radius of the attack.

Multi Acid Projectile - Ryatroxos gets low to the ground and fires 3 corrosive projectiles from its tail towards its targets dealing moderate damage and leaving acid gas at the area of impact, inflicts corrosion.

Tail Swipe - Ryatroxos swings its tail from side to side in an attempt to hit its foes dealing moderate damage, can inflict stun.

Trample - Ryatroxos runs around quickly towards a hunter in a similar manner to Zinogre dealing moderate damage and inflicting stun.

Head-butt - A heavy hitting attack where a hunter is hit with the full force of an Atroxlong horn like crest knocking them back and inflicting stun.

Tail Spin - Ryatroxos spins around in a similar manner to Tigrex in an attempt to hit a hunter with its tail dealing moderate damage and a chance to inflicting stun.

Acid Mist - Ryatroxos will spew a mist of acid from its scutes that will linger in the area and deal continuous damage to hunters caught in the mist. Inflicts corrosion.

Corrosion Tail Slam - Ryatroxos will slam its tail into the ground leaving temporary puddles of acid on the ground.

Duel Acid Tail Slam - Ryatroxos slams its tail into the ground twice leaving two temporary acid puddles on the ground.

Bleeding Bite - Ryatroxos will quickly bite the hunter dealing moderate damage and inflicting bleed.

Pin - Ryatroxos will lunge at the hunters. If the attack is successful Ryatroxos will grab the hunter with its jaws, shake its head from side to side with the hunters trapped in its maw and then throw them to the ground dealing high damage and inflicting bleed.

Claw Swipe - Ryatroxos will swing at a hunter with its powerful arms, can be done multiple times with each arm and has a chance to inflict stun.

180 Bite - Ryatroxos will quickly turn around towards a hunter and give a quick bite, can be done more than once has a chance to inflict bleed.

Tail Slam - Ryatroxos slams its powerful tail into the ground causing the ground to shake.

Back Slam - Ryatroxos jumps up and slams into the ground with its back dealing high damage and inflicting stun.

Pounce - Ryatroxos will leap towards a hunter and land on them dealing high damage.

360 Bite - Ryatroxos spins around with its jaws dealing heavy damage and inflicting bleed.

Enraged Attacks

Corrosive Pounce - Ryatroxos claws start to drip with highly corrosive acid and dragon energy. Aroxlong will lunge at hunters with its claws hoping to gore them dealing massive damage and causing an explosion of corrosive acid and dragon energy in the nearby area. Inflicts corrosion and dragonblight.

Thermal Stream - Ryatroxos fires a powerful concentrated stream of acid and fire that explodes violently when hitting the ground dealing massive damage. Inflicts corrosion and fireblight.

Atrox Fire - Ryatroxos fires out a concentrated ball of fire at foes dealing high damage and inflicting fireblight.

Thermal Mist - Ryatroxos ignites the acid on its body causing a huge wall of flame to pulse from its body dealing high damage and inflicting severe fireblight.

Back Flip Slam - Ryatroxos jumps in the air and slams its bladed tail into hunters dealing high damage.

Super-heated Bite - Ryatroxos lunges at a hunter with its jaws engulfed in flames and then bites down creating a shock wave of fire deals high damage and inflicts fireblight.

Acidic Tail Bomb - Ryatroxos stabs its tail barb into the ground and injects its acidic venom into it causing geysers of corrosive gas to spew from the ground around it, Ryatroxos than quickly jumps into the air and fires a flaming projectile towards the ground causing a massive explosion that deals heavy damage and inflicts corrosion and fireblight, can easily one shot hunters.

Inferno Wall - Ryatroxos spins around dragging its tail across the ground leaving a trail of corrosive fluid on the ground Ryatroxos will then ignite said trail causing a massive wall of fire to rise. While inside Ryatroxos will release eject a mist of acid causing the wall of fire to violently pulse in all directions.

NOTE: All of Ryatroxos physical attacks now inflict corrosion when it is in its first enraged state, but when in its second it inflicts fireblight.

Breakable parts / Damage Effectiveness (WIP)


  • Base HP: 5,000 HP
  • Low-Rank: N/A
  • High Rank: N/A
  • G-Rank: N/A

Breakable Parts

  • Crests
  • Back Spikes
  • Underbelly
  • Legs
  • Tail

Physical Damage Effectiveness

  • Head = ★ (Cutting) ★ (Impact) ★★ (Shot)
  • Torso = ★ (Cutting) ★ (Impact) ★ (Shot)
  • Legs = ★ (Cutting) ★★ (Impact) ★ (Shot)
  • Tail = ★★ (Cutting) ★ (Impact) ★(Shot)

Element Effectiveness

  • Fire = ✖
  • Water = ★★★
  • Thunder = ★
  • Ice = ★★
  • Dragon = ★
  • Earth = ★
  • Wind = ✖

Status Effectiveness

  • Poison = ✖
  • Sleep = ★
  • Paralysis = ★
  • Blast = ★★
  • Stun = ★
  • Blind = ★
  • Corrosion = ✖

Shiny Item Drops

  • N/A

Material Items

  • N/A

Slinger Ammo

Ryatroxos drops bomb pods and corrosion pods.



Rarity Name Attack Affinity Sharpness Slots Element/Ailment Description Cost
Great Sword Icon Green
Atrox Jaw Blade 1253 +10% Green/Blue/Blue oo- 150
Element Fire
A large blade made from Ryatroxos materials, the heat helps the blade cut down its foes!
Dual Blades Icon Green
Mandibular Daggers 750 -10% Green/Blue/Blue o--
Status Corrosion
Fearsome bladed weapons that uses the venom glands of a Ryatroxos. Even the mightiest of beasts stand no chance against such blades.
Hammer Icon Green
Maxillia Smasher 1920 +20% Green/Blue/Blue ---
Element Fire
A mighty hammer crafted from the jaws of a Ryatroxos. It is said this hammer can crack open even mountains!
Charge Blade Icon Green
Indomitus Tyrannus 960 -20% Green/Blue/Blue ooo
Status Corrosion
  • Impact Phial
A legendary weapon used by the most powerful of tyrants. One swing is said to take out an army.


High Rank Carves

Icon Name Description
Fang Icon White


A large grooved fang designed to inflict deep wounds and and tear large chunks out of prey.
Hide Icon Light Green
Ryatroxos Hide+ A thick, durable and acid resistant hide of an Ryatroxos perfect for shrugging off even the most fatal of blows.
Sac Icon Dark Green


An organ from a Ryatroxos containing the most toxic and caustic substance known to man!
Sac Icon Red

Inferno Sac A monster organ filled with powder that ignites if it so much as touches air. Danger!
Scale Icon Red
Ryatroxos Scale+ A hard scale carved from an Ryatroxos hide that is surprisingly heavy for its size.
Carapace Icon Dark Red
Ryatroxos Shell+ A carapace formed from thick layers of scales over a single rigid bone give Ryatroxos all the armor it needs.
Horn Icon Grey
Ryatroxos Scute+ A hard horn like scale that can be found atop an Ryatroxos carapace. Is known to be filled with the beasts acidic venom.
Claw Icon Black
Ryatroxos Talon+ A large, sharp and sturdy claw carved from an Ryatroxos fore limb. It is sharp enough to cut steel!
Monster Parts Icon Red
Ryatroxos Crest+ A pair of horn like crests carved from an Ryatroxos, sturdy and hard. These structures are used to show this beast unquestionable dominance.
Bone Icon Red
Ryatroxos Hardbone+ A hollow, air sack filled bone that is surprisingly strong and sturdy, this adaptation helps explains how Ryatroxos is able to be so agile for its large size.
Monster Parts Icon Red
Ryatroxos Tail+ The tip of the Ryatroxos tail is covered in three bone blade like scales that it uses to disembowel foes with.
Scale Icon Dark Red

Ryatroxos Plate A rare scale that is warm to the touch and filled with toxic acid, used in crafting the highest of quality gear.

G-Rank Carves:

Coming soon....


Interactions with Other Monsters

Low Tier Monsters

  • Ryatroxos vs Great Jagras:
  • Ryatroxos vs Great Girros:
  • Ryatroxos vs Dodogama
  • Ryatroxos vs

High Tier Monsters

  • Ryatroxos vs Bazelgeuse: The two monsters become enraged and start to size each other up while roaring. Ryatroxos attempts to lunge at Bazelgeuse, only for it to miss as Bazelgeuse takes to the air. The Bazelgeuse primes its scales as it circles Ryatroxos in the air and quickly divebombs the fearsome fanged wyvern creating a massive explosion with its primed scales dealing high damage (1500-2000) to the Ryatroxos, only for the Ryatroxos to quickly recover and pin the grounded Bazelgeuse to the floor with its powerful forelimbs dealing moderate damage (300-500). The Ryatroxos roars and proceeds to maul the pinned Bazelgeuse dealing very high damage (2500-3500) and then proceeds to roar in victory as it throws Bazelgeuse across the ground with its powerful forelimbs. Both monsters then proceed to idle and take a breather and then both leave the area.
  • Ryatroxos vs Deviljho: The two become enraged and start to roar at each other. The Deviljho impatiently lunges towards the Ryatroxos and grabs it by the back of the neck and proceeds to slam and drag it across the floor dealing high damage (2500-3000) to the Ryatroxos, the Deviljho then attempts to lift the Ryatroxos once more only to have its face viciously clawed by the Ryatroxos powerful arms dealing moderate damage (300-500) causing the Deviljho to release the Ryatroxos and writhe in pain. The Ryatroxos then takes advantage of its staggered opponent and topples the Devilho by pouncing on the brute wyvern. The Ryatroxos begins to effortlessly maul the helpless Deviljho and deals high damage (2600-3100). The Deviljho then manages to knock the Ryatroxos off its body and the two monsters then proceed to roar at each other. The conflict ends with both monsters leaving the area.
  • Ryatroxos vs Tautogoth: The two monsters begin roaring at each other and become enraged. Ryatroxos then begins by spitting a stream of fire at Tautogoth dealing moderate damage (500-600). The Tautogoth then uses one of its arms to block the toxic flames while the other reaches into the ground and pulls out a boulder. The Ryatroxos then stops its fiery assault and roars, the Tautogoth takes advantage of this and leaps towards Ryatroxos and slams an explosive rock into its face causing it to fall on its side and dealing high damage (2500-3500). The Tautogoth then prepares to stomp on the fanged wyvern only to miss as Ryatroxos quickly recovers and leaps onto Tautogoth and clamps its jaws around the bypaldians neck dealing high damage (2500-3500). The Tautogoth then quickly responds with a swift punch to the fanged wyverns throat dealing moderate damage (500-600) and causing the Ryatroxos to lose its grip and fall backwards. The two monsters become exhausted from the fight and both leave the area.
  • Ryatroxos vs Rajang:
  • Ryatroxos vs Kuroshen: The two monsters start to roar at each other and circle one another. Ryatroxos then attempts to lunge at Kuroshen only to miss as the Kuroshen quickly dodges the attack. The Kuroshen then jumps onto the back of the larger fanged wyvern and begins to viciously maul at the back of the neck dealing high damage (2500-3000) while the Ryatroxos attempts to get the smaller creature off its back. The Ryatroxos then releases a mist of corrosive venom from its spines which stagers the Kuroshen and deals moderate damage (500-600) and then grabs a hold of the smaller fanged wyverns legs with its jaws and then proceeds to pull it off and throws it to the ground dealing high damage (2000-2500). The two fanged wyverns then roar and leave the area.
  • Ryatroxos vs Odogaron:
  • Ryatroxos vs Tigrex:
  • Ryatroxos vs Ferrumos:
  • Ryatroxos vs Sicarapax:
  • Ryatroxos vs Rathalos/Rathian:

Interactions With Unique Statuses (Frenzy/Apex, Hyper Status, Tempered Status, Fanon Status, etc)



  • Ryatroxos love the taste of Kirin and its relatives.
  • The fire Ryatroxos produces is green in color unlike that produced by other fire monsters, the reasoning behind this is due to the chemicals found in its unique acidic venom.
  • Ryatroxos has no low rank carves as it can only be encountered during high rank quests and above.
  • When it is enraged acidic mist covers its whole body and arms and its upper body bursts into flames.
  • Ryatroxos is based on multiple species of animals both extant and extinct!
    • Some of the animals it is based on includes theropod dinosaurs like Giganotosaurus. It also has features based on the prehistoric crocodile and dinosaur relatives Saurosuchus and Fasolasuchus. Some modern animals that provided some inspiration for some of Ryatroxos features are Horned Vipers.
  • When low on stamina Ryatroxos will either hunt smaller monsters, feed from a carcass or feed on weakened, sleeping or dead large monsters.
    • Ryatroxos will feed from dropped raw meat when low on stamina, it will not however feed from poisoned, tainted or drugged meat even if it is low on stamina.
  • Ryatroxos tail can be severed after it is scarred.
  • Ryatroxos Crest and head can be damaged.
  • Ryatroxos roar requires HG earplugs to block.
  • Ryatroxos is one of the few monster with the power and ferocity to actively hunt other large monsters such as Validoth and Sicarapax!
  • Ryatroxos are a rival species to Ferrumos and often compete violently to become top predators of a region.
  • Ryatroxos was originally called Atroxlong and was a Brute Wyvern.
  • Despite being classified as Fanged Wyverns, Ryatroxos isn't closely related to any other monsters of that classification save for its close relative Anatroxos and the mutant Charred Ryatroxos variety .


Ryatroxos theme (MH2dos Tower? BGM)

Ryatroxos theme (MH2dos Tower? BGM)