I'm going to let you in on a secret. That secret is how to construct the best (worst?) insults.
(Rude word)+(everyday activity) (rude word)+(creature or object)
It's a simple formula even you poop-gargling buttgoblins can manage. In fact, the more pathetic and childish your attempt the more effective your insult is likely to be. Can anyone resist the urge to giggle when presented with a stinky-faced snotdragon? Clearly not.