One of the unlockable pets from the puzzle game Insaniquarium. He fights enemy aliens on the ground.
Rufus the Fiddler Crab
Crab/Shrimp/Lobster
for Crab/Shrimp/Lobster in Fictional animals by species
Suggested by xylopiano
Obviously, don't nominate any human characters. Hybrids like Cheetah or The Lizard are okay, as are shapeshifters with one set animal form (eg Professor McGonagall.)