Wolverine's first & Origin occured in the Incredible Hulk #180, October 1974 issue (Incredible Hulk Volume 1).

Wolverine's cameo in this issue was limited to a single panel intro. He appears in full in the next issue in November 1974, Incredible Hulk #181 which is often referred to as First & Full.

In this issue #180, the Hulk is trapped in a cave, fighting the Wendigo. In the final panel, a clawed creature is shown entering the battle which we learn in the next issue is Wolverine.