Eliminators, known as Player Killers (プレイヤーキラー Pureiyā Kirā) in the manga and Japanese version, were duelists employed by Maximillion Pegasus for the Duelist Kingdom tournament. Their role in the tournament was to challenge the contestants to a Duel, and if the Eliminator won, they took the Star Chips the contestant had wagered. Like a normal Duel, if the duelist bet all of his or her Star Chips and lost, that disqualified the duelist from the tournament.
Pegasus hired the Eliminators to ensure that only four finalists could reach Pegasus Castle. As there were eighty Star Chips in total issued (with ten required to enter the castle), the Eliminators' duty was to retrieve the extra forty Star Chips, to ensure no more than four finalists could enter. In the case of the Ventriloquist of the Dead/Ghost Kaiba, he was assigned primarily to defeat Yugi Muto, as his imitation of Seto Kaiba was intended to put off Yugi. There was a particularly high bounty placed on Yugi, as PaniK noted.