Origin of Wolverine, specifically the first time he is referred to as Weapon X in the chronological order of the story
Though the character introduced in Incredible Hulk #180 (1974) was named The Wolverine aka Weapon X, an origin story hadn't been developed yet
One enduring rumor was that he was initially meant to be the actual animal, evolved with the assistance from the High Evolutionary but this was dispelled by Len Wein, the writer who is credited for creating the character