Pierre Dupont is a villain in Tomb Raider and Tomb Raider: Anniversary. He also haves a minor role in Tomb Raider: Chronicles.
Tomb Raider
In Tomb Raider he is portrayed as being a french treasure hunter who pursues ancient ancient artefacts only for the money and fame, not for the glory. He is hired by Jaqueline Natla to retrieve the four pieces of the Atlantean Scion before Lara Croft does. He meets Lara in Greece and starts a fight with her over who will possess the Scion, Lara eventually kills him and takes the artifact.
Tomb Raider: Chronicles
Pierre re-appears in Tomb Raider: Chronicles although this is considered to be chronologically based before the events of Tomb Raider. He is searching for the philosopher's stone in Rome with Larson Conway and finds out that Lara possesses the stone. He and Larson run after her and try to steal it off her. Pierre is last seen being forced by Lara against the end of a cliff when she gives him a scare and leavs him hanging from the cliff, soon after Pierre falls to his apparent death. Although Tomb Raider: Chronicles is based in the original game's continuity there are some inconsistency errors, for example when Pierre falls from the cliff we clearly ear the impact of pierre's body with the ground and the fall would be almost impossible to survive because of the height, never the less it's a game so improbable events may occur.
Tomb Raider: Anniversary
Although Anniversary is a remake of Tomb Raider some events unfold in a different way. In the original game Pierre is killed by Lara but in Anniversary he is stomped to death by two centaurs in Greece. His look also changes from having fairly long hair to being completely bald.