Gilashark

Well, who's gonna get this gilashark off me?

Gilasharks are a lizard-like alien species. They are typically afflicted with acrophobia.

Fiction

Marvel The Transformers comics

At least one Gilashark was a performer in the space-travelling circus known as the Cosmic Carnival. He attacked Sky Lynx and Optimus Prime on orders of Big Top when the Autobot leader tried to help his fellow Autobot escape. Sky Lynx only had trouble fighting him off until he figured out the thing was afraid of heights. The Cosmic Carnival