Ibac
A frail thug named "Stinky" Printwhistle who was empowered by Lucifer himself after he was saved from a fall caused by Captain Marvel, with the powers of four of the most evil men to walk the face of the earth (Ivan the Terrible, Borgia, Attila the Hun and Caligula). When he says the name "IBAC", he becomes a large, muscular brute with super-strength. Saying his name again transforms him back into Printwhistle (therefore, like Captain Marvel, Jr., Ibac also cannot say his own name).
Read more about this topic: List Of Marvel Family Enemies