Anton Gris
From Tomb Raider Wiki
Anton Gris is a heavy set man, and a character from Angel of Darkness. He runs a gym and boxing club in St Aicard's Church, once the local parish of the Parisian Ghetto.
Lara can interact with him by betting on one of a pair of boxers in the ring. Two hundred euro is the stake, and if you win you get his gold watch, which can be pawned. Otherwise he has no bearing on the storyline.
It is generally accepted that he works for, or at least with, Louis Bouchard - perhaps offering him a cut of any boxing prizes that his trainees win. From official game information, he comes originally from Marseille in the south of France.