The Hopple is a small, weak enemy that spawns very commonly in worlds where it lives. It sometimes randomly hops. They look like this: (sorry about the small image size) Some Hopples (less than 1%) aren't actually Hopples, but there's no way to tell until it's too late. They're Hopplegangers! Hopplegangers are a very powerful, strange looking enemy that a Hopple transforms into after getting close to the player. (image pending)
The Venus Bonk Trap of Starbound. I like it. From what I can see of the sprite it looks like a frog. Maybe have the real Hopples blink and the Hoppelgangers just stare? It's one pixel, so it would be hard to tell.
