Mutant Bat

The Mutant Bat was a creature which appeared in the Ben 10 animated series episode Chicken Nuggets of Wisdom.

Description
Once a regular bat, the Mutant Bat had been grown to enormous size by Ben Tennyson's long-time adversary, the mad scientist Dr. Animo, who used an echolocation device to transform his thoughts into sonic commands which the Bat could understand. It was capable of high-speed flight and could use its natural sonar as a devastating weapon.

History
Whilst flying on the back of the Mutant Bat across a forest and monologing about how his hatred for Ben Tennyson was all in the past, Dr. Animo was rudely interrupted by fireballs cast into the air by a petulant Ben in his Heatblast form who was trying to blow off some steam. Quickly reversing his view on the child hero, the enraged doctor commanded his Bat to attack Ben while he went after Gwen and Grandpa Max.

Ben, who by now was stuck in his Diamondhead configuration, soon discovered the unpleasant reality that the Bat's sonar was capable of cracking his crystalline form. However, he was eventually able to subdue the beast before it was dragged off by the authorities (who had covered its ears with Grandpa Max's mufflers to prevent Animo from commanding it to help him escape).