Tu'Pari is a Narn and member of the Thenta Makur. In 2258 he was hired by Du'Rog to kill Ambassador G'Kar, one of his enemies in the Kha'Ri, upon his death. Like all members of the assassin's guild, he left a black flower (or "death blossom") near one of his intended victims so they knew to get their affairs in order.
Tu'Pari assumed the identity of a diplomatic courier en route to Babylon 5 after killing him. He gave G'Kar a message from Du'Rog which explained that Du'Rog had hired an assassin to kill G'Kar which, upon completion, Tu'Pari incapacitated G'Kar and removed him to an isolated location on the station.
G'Kar's new ambassadorial aide, Na'Toth realized what was going on and prevented the death of G'Kar. Knocking out Tu'Pari, they left him unconscious until after the appointed time agreed to by Tu'Pari and the Thenta Makur for G'Kar's death. G'Kar deposited money into Tu'Pari's account to make it appear that he had been bribed into not killing G'Kar, scandalizing the Thenta Makur.
Upon hearing this, Tu'Pari realized that his life was all but over as the Thenta Makur is not a forgiving organization.
Tu'Pari's sole appearance was in The Parliament of Dreams.