*Wolverine vs. Sabretooth: Although the cause of their hatred is unclear, what is certain is that both the mutant hero Wolverine and the savage mercenary Sabretooth were transformed by the scientists of the super-secret Weapon X project into the perfect killing machines. But while Wolverine chooses to use his lethal abilities in the cause of justice, Sabretooth is committed to a life of crime. The two have clashed repeatedly---and neither man will rest until the other is dead.
First Encounter: Uncanny X-Men #212, December 1986
*Source: Back of card