Another ben 10 alien is Ripjaws. Ripjaws is a ferocious mix of alligator, eel, anglerfish and shark. His main ability is being able to breathe underwater. He is also able to swim at great speeds, and his sharp teeth and claws can pierce through almost anything. Since he is a combination of some aquatic life forms, his main weakness is dehydration. So, it s clear why he is the least used Omnitrix alien.