Fighting like pineapples and dogs.
Imagine that you're seeing a pineapple for the first time. Would you look at that thing—with its knife-like leaves and its thorny, uninviting skin—and think to yourself, "Mmmmmm... That looks like something that I'd like to mix with some rum and coconut to make into a smooth and refreshing summertime treat," or would you more likely yell out, "Kill it now before it turns on us!"?
You don't have to answer right now. Just mull it over while you watch Stella the pit bull's first run-in with this strange and aggressive tropical fruit: