A formidable aquatic serpent that crests on moonlit nights—likely why it has often been mistaken for a mermaid. Despite its appearance, it is extremely aggressive, and tolerates no trespassers on its turf. It expels an intoxicating sleep powder from an organ on its neck, knocking out prey before it can resist.

Somnacanth is a Leviathan first introduced in Monster Hunter Rise.


Somnacanth is a Leviathan with a very unique physiology. Covering its body are large yellowish scales, transitioning to white on the underside. Its front feet have three digits, each one ending in a long, curved black claw. Its back feet have four digits that end in shorter claws. It has fins on each front leg. It has a short face with a disturbingly humanoid appearance. Above its eyes are a pair of large purple horns, with a pair of smaller knob-like protrusions in front of them. Adorning the side of its head are three pairs of small purple fins, with a massive crest-like fin on the top. These purple fins also appear along the top of its tail and form a crescent shape at the tip. It has a hard pad on its belly with a taiko drum-like pattern that it uses to crack open shells. It also features several bioluminescent patches on its body, which can be seen around its eyes, in the mouth, the seams on the throat, and the underside of the tail base.

Behavior and Abilities

Somnacanth can often be seen swimming on its back. It is capable of standing on its tail. It is a very territorial creature, tolerating no trespassers, and can become extremely aggressive.

Somnacanth is capable of producing a sleep-inducing powder in its throat and spraying it through the mouth. Similar to other monsters that can put creatures to sleep, it will use this opportunity to strike at its prey or adversary. It can breathe this powder out as a long ranged, sweeping cone or as a large cloud that covers the whole area. It is capable of jumping high into the air and slamming down on its target. It can also throw dart-like quils in rapid succession. The quils linger on the ground for a few seconds. The darts originate from the end of its crest.

During combat, Somnacanth has a tendency to stand on its tail, keeping its head hard to reach.

It can use its hard belly to crack open shells while laying on its back, similar to otters. These shells have a variety of effects when cracked open, including an explosion that covers hunter in blast powder, a directional flash and even a healing mist that also heals nearby hunters.

In-Game Description

Monster Hunter Rise
MHRise-Somnacanth Icon.png A formidable aquatic serpent that crests on moonlit nights—likely why it has often been mistaken for a mermaid. It expels an intoxicating sleep powder from its neck gills and tail, knocking out prey before it can resist. Some Somnacanth sightings tell of this species making use of unusual shells, so exercise caution if you catch one swimming towards you with a shell in its claws.
Threat Level (危険度): ★★★★★


  • Somnacanth is based off of a mixture between Western and Japanese mermaids from folklore as well as sea otters.[2]
  • Somnacanth was originally teased by Ichinose on the official Monster Hunter Twitter.[3]
  • Its crest and tail can be broken. Each foreleg can be broken individually.
  • Its English name, Somnacanth seems to be coming from the Latin word Somna- meaning "fall asleep", which could be a reference to the monster's ability to use sleeping gas. -canth is a common taxonomic affix that means spine, but is most famously associated with fish such as the coelacanth.


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