Hey, a character who actually debuted in a comic book that Ditko drew, and that Ditko presumably might have had a hand in designing. Go figure. Anyway, the character first appeared in Ditko's final issue of MACHINE MAN some years before this, and subsequently became a Spider-Man villain. Pretty cool design, overall. I always did wonder, though, given the similarities in design, if there was some intention to use the Green Goblin in that story, changed for understandable reasons. The comparison isn't helped by the character subsequently becoming an even more blatant Green Goblin derivative, the Hobgoblin (a fact which made his first appearance harder to find at a reasonable price back around the time I was first getting Ditko MACHINE MAN back issues).
As usual for this series, Joe Rubinstein provides the inks.