32 - Giant Beaver


Common Name Castoroides
Group Mammals
Species Castoroides feliconcisor
Time Late Pliocene & Late Plestocene
Diet Herbivore
Temperament Friendly
Feces Size Medium
XP For Kill 4 XP
PC Release Date February 24, 2016 (v236.0)
Xbox Release Date March 7, 2016 (v732.0)
Favorite Kibble Kibble (Gallimimus Egg)
Tameable Yes
Rideable Yes
Saddle Castoroides Saddle (lvl 55)
Gestation Time 7h 56m 11s
Baby Stage Time 6h 10m 22s

Castoroides is a large, mammalian herbivore that tends to live near water. Unlike other larger beaver species this one retains the chisel-shaped teeth of modern beavers. As is typical for beavers, they build dams as habitats, but the larger creatures on the island have a tendency to trample them. As a result, finding unsullied dams in the wild is quite rare.

Castoroides itself doesn't seem to realize how dangerous the island is. I don't know if it's simply too dumb to notice the dangers, or if it just doesn't care, but Castoroides happily goes about its day playing in the water and gnawing on wood.


The value of a tamed Castoroides is obvious from its physiology. The creature naturally gathers wood extremely efficiently, far more than most species on the island. It's not the strongest creature, so it can only carry limited amounts, but it is a natural lumberjack!

— The Dossier

The Castoroides or Giant Beaver is a medium sized herbivorous mammal found on the Ark.

Wikipedia has a more detailed and comprehensive article on Castoroides


The Castoroides is a giant species of beaver found commonly in the rivers and ponds of the island's interior. It also appears at the Hidden Lake. It has waterproof fur and a flat tail for swimming. With their powerful jaws and sharp incisors they can gnaw through many of the trees found throughout the island, using the resulting wood and other raw materials to construct their dams.


Wild Castoroides will build dams containing large quantities of wood, cementing paste, rare flowers, rare mushrooms, and silica pearls. Castoroides are very protective of their dams and will come to their defense should anyone threaten them. One to three beavers have been noted around a dam site.

Castoroides will not attack any entity (whether it be player or creature) unless aggravated to do so. Often, Giant Beavers who reside close to swamps will be forced to defend their territory and fight against wandering Dilophosaurs and invading Titanoboas. Sometimes they can be seen grouping up against larger predators like Carnos or swarms of smaller predators like Raptors and Terror Birds. If a player attacks one, the entire Giant Beaver population in the immediate area will attack. Unless injured by the player, a player can get as close as they would like to a Giant Beaver. If the ability to kill a Beaver in a single hit by a powerful mount is available, doing so will not make the other Beavers attack.





  • The dossier was revealed on June 20, 2015.
  • Before the introduction of the Direbear and the Redwood Forests with Megaloceros in it, hunting Castoroides is the easiest way to gather Pelt outside the tundra. Keep in mind that they are rather rare, however, and may be worth more alive than dead.
  • In life, Casteroides' incisors were much broader and thicker than modern beavers, so they would have been less effective at cutting wood. For this reason, many paleontologists believe they did not construct dams.
  • Can be picked up by an Argentavis and Quetzalcoatlus.
  • Despite having the oxygen attribute, it never drains when the beaver is underwater. Thus beavers are incapable of drowning.
  • When riding a Castoroides in first person view, the camera is placed slightly behind where it should be, as you can clearly see its saddle.
  • In real life the beaver reached a maximum length of 2.2 meters. In-game this is 3.75 meters.
  • A map of giant beaver dam spawn locations can be seen in the article Giant Beaver Dam. These are also good locations to find beavers, as they spawn in pairs around the dens.


Gameplay Images



Spotlight Castoroides!-0

Spotlight Castoroides!-0