As an aggressive, venomous, and trouser-ruiningly huge tarantula, Xenesthis immanis has no trouble murdering just about anything it wants. Small, furry mammals are nothing more than fast food, and it can even kill and eat venomous snakes simply by biting first. It's pretty much the last animal you'd expect to keep a loving, loyal pet. And yet, Xenesthis immanis has made itself a best friend in the form of a tiny, adorable, dopey-looking frog named Chiasmocleis ventrimaculata.
This frog is so teeny and vulnerable, even Kermit could slap it around. They're aware of this, too, doing just about anything to survive, from living under massive mounds of elephant s**t to living under the figurative thumb of an eight-legged murderer.
Keep in mind, they eat other frogs.