Amazing Spider-Man (1963 1st Series) #110
First appearance of the Gibbon in "The Birth of the Gibbon!" Part 1 of 2. Script by Stan Lee. Pencils by John Romita. Inks by John Romita and Tony Mortellaro (backgrounds). Cover by John Romita and Frank Giacoia.
On a Manhattan rooftop, the wall-crawler has a chance meeting with a man named Martin Blank. And after he talks with Spider-Man; the tall, lanky, and athletic Martin decides to become a superhero! But when Martin (in his ape costume) meets the web-slinger again, Spider-Man laughs at his offer to become partners, and Martin is hurt. And now the Gibbon is vulnerable to becoming partners...with someone else! Origin of the Gibbon.
32 pages. Cover price $0.20.