Krulos

Krulos is an evil frog-like alien, leader of the Rulons, and main antagonist of the Dino Riders toy series and cartoon.

Revenge against Questar
As revenge against Questar, he joined forces with Dr. Claw (who sounds like him), Divatox, and Meowth in order to keep peace in Evilland, a planet full of evil things. He rode on a tyrannosaurus rex which is similar to Sharptooth in appearance. He and Mon*Star once joined forces to defeat the god Thor.