Bushrats

The common Bushrat of Mars is similar to the Earth rat: an annoying pest.

Description
Despite the sharp beak, a single bushrat is no threat at all. Too bad that they usually travel in huge packs to overwhelm their prey, which is when they do become a problem. The bushrat is also strange since despite being a plantimal, it lives above and below ground. This indicates that it doesn't need sunlight, unlike other plant animals.