For me, it's the bullfrog. Back when I was a kiddo, we had a pond in the woods in the backyard. I'd go down very often, and catch all kinds of various frogs and toads. However, there was this one big motherfucker of a bullfrog down there. He'd show his just his eyes above the surface of the water, taunting me to just catch him. One day I'd had enough. I decided to wade out to grab him. Sadly, I didn't understand just how deep you can sink into a muddy pondbed. I had my gameboy in my pocket, and on that day I broke the charging port and lost out on catching the bullfrog.
As a frog, the bullfrog has my respect. They are not to be fucked with.