Dr. Mortal isn’t precisely a super villain. He doesn’t have a costume or a moniker per se, just a funny name and a lab coat. On the other hand, he does use mutated claw-dwarfs and trained vultures to commit crimes, so all the pieces are there.
References: [The Flame #4] [1941] [“Dr. Mortal: Brilliant scientist and enemy of mankind carries on his weird experiments …”; has a flock of trained vultures; uses meteorite to transform his worker into a “claw-dwarf”; “My challenge was proclaimed! Now let them beware!”; foiled by his beloved niece marlene and her boyfriend gary; ]
Metahuman Database 