clockwise from top-left: dr. venture, the monarch, molotov cocktease, dr. quymn
And that’s leaving out Dean and Jonas Jr., both of whom have that kind of brown hair that looks kinda-sorta red. But they’re related to Dr. Venture and therefore less notable. And, of course, there’s apparently a popular theory that Venture and Quymn are actually siblings as well. Still, the fact that the family patriarch, his arch-enemy, and the series femme fatale would all have red hair is a little weird.