Misunderstood Instruction

Alright, listen up, buttercup. The joke here is that the dude's friend told him to "beat that pussy up." Now, a normal, smart cookie would know that "pussy" is slang for "vagina." But our friend here? Oh no, he went and actually beat up a cat! Hence, animal control knocking on his door. You probably have that one friend who always takes things too literally, and it's probably you.