Sabretooth (a.k.a Victor Creed) Is much like wolverine minus the pussy morality bit
Sabretooth is the primary villan and counter part to the X-mens Wolverine. That being said he has faced off against the majority of the marvel universe including the x-men, spiderman, captain america etc. Unlike villans such as Doctor Doom and Magneto Sabretooth doesnt really have any overall goals other than taunting wolverine and killing anyone or thing that crosses his path. Over the years its been hinted at that sabretooth and wolverine were either friends, father and son, brothers but nothing was ever decided on because commiting to a storyline is for suckers.
Over the years Sabretooth has taunted wolverine on his birthday every year regardless of where wolvie is in the world. Clearly Sabretooth has nothing but time on his hands. Sabretooth holds the title of killing wolverines first love Silverfox, Injuring his team mates, kidnapping and almost killing his sidekicks and copying his sideburn styles.
Last year wolverine finally had enough and killed Sabretooth with a blade that cancels out healing factors. By this point sabretooth had lost his humanity and asked to be killed. Since this is a comic universe and wolverine always needs someone to stab over a long period of time we can be sure sabretooth will be back within a year or two.
Sabretooth has appeared in two movies played by different actors. In the first X-men film Sabretooth is a mindless thug portrayed by Tyler Mane who ends up getting blasted off the Statue of Liberty by Cyclops after a fight with Wolverine. In the new X-men Origins: Wolverine he is played by Liev Schriber as a cunning and violent half brother to Hugh Jackmans Logan. Rumours of his return in the upcoming Wolverine sequel have been greeted by alot of fans who found Schribers portrayal one of the best parts of the first movie.