Floyd Mangles, mostly known by his alias Doctor Angst, made his first appearance as a criminal magician sent to assassinate presidential candidate Howard the Duck. Assembling a team of pathetically powered individuals under the banner "Band of the Bland", Angst make short work of Doctor Strange, leaving Howard to confront Angst alone as the Temporary Sorcerer Supreme of the Earth Realm. In a cataclysmic battle inside of Shea Stadium, Howard led the Defenders to victory against Doctor Angst and his Band of the Bland.
Doctor Angst would later return in an attempt to enact a devastating "Cosmic Squish" upon the Marvel U in an attempt recreate the known universe. As we all know, when evil arises, so do those who seek to battle it... this time in the form of the sensational She-Hulk and (you guessed it) Howard the Duck!
Another Dr. Angst
In Spectacular Spider-Man, a new character dorning the name of Dr. Angst was introduced. Pay attention that this character has nothing to do with Mangles or Howard the Duck.