Grasshopper Mice

They may be bitey and stink to high heaven, but you've got to admit grasshopper mice (Onychomys spp.) are badass:

1. They regularly hunt and eat scorpions, one of the few carnivorous New World rodents
2. They can turn off pain signals from scorpion stings
(Research paper at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4172297/)
3. And they howl like wolves to advertise their territory