Etrigan the Little Devil

When I was in grade school, I used to buy black and white reprints of Harvey Comics. My favorite was Hot Stuff, the Little Devil. He appealed to me more than Casper, since I found Casper to be a bit depressing (a ghost who just wanted to have friends but more often than not scared those he wanted to befriend). So I guess the answer to the question on the cover above is "Turned him into Hot Stuff."