Chris Claremont had meant for Sabretooth to be Wolverine's father, though this was disproved by subsequent writers. Claremont, when asked what he had intended to be the relationship between Wolverine and Sabretooth, stated:

Father and son. That's why Sabretooth always considered Logan "sloppy seconds" to his "original" / "real deal." The other critical element in my presentation of their relationship was that, in their whole life, Logan has never defeated Sabretooth in a knock-down, drag-out, kill-or-be-killed berserker fight. By the same token, on every one of his birthdays, Sabretooth has always managed to find him, no matter where Logan was or what he was doing, and come within an inch of killing him. For no other reason than to remind him that he could."
In Wolverine Vol. 2 #42, tests performed by S.H.I.E.L.D. confirmed that Sabretooth and Wolverine were not father and son.

An interviewer asked Paul Jenkins if the character Dog Logan, a character from Wolverine's early life, from the limited series Origin was Sabretooth. Paul Jenkins said he had not intended it to be him, but said he wouldn't have a problem with another writer doing it later.