Mosquito

Mosquito was the arch nemesis of Thunderman. Thousands of innocent lives were killed by this vicious enemy. He contributed much time and effort in seeing that Thunderman was despised by civilians before escaping, never to be seen again.

In "Legend", Mosquito never made an appearance, but instead was only briefly mentioned when Old Thunder was telling Super Scott about his history, and then later when Adam Prune was giving examples of reasons why super-powered beings needed to be exterminated.