The Ghouls (グールズ in Japanese and صــائـدوا النـوادر in Arabic) or Rare Hunters (4Kids dub) are Marik Ishtar's henchmen and a major antagonistic group in Yu-Gi-Oh! Season 2. The Ghouls were formed by Marik Ishtar to collect the Egyptian God Cards and other cards of value, becoming a group with money and power to grant Marik power. It is not specified exactly when they are formed, but it was some time after Marik killed his father and left with Rishid the following day. The Ghouls are known to be Marik's henchmen and assist him in his goals with Rishid Ishtar being the second in command.
They were known to have stolen two of the three Egyptian Gods, but failed to steal the Giant God Soldier Obelisk, thanks to the intervention of Ishizu Ishtar. Also, they have counterfeited rare cards, including the Winged Divine Dragon of Ra and the five pieces of Exodia.
The first Ghoul to appear (although not addressed as one and was brainwashed by Marik) is "Bandit" Keith Howard, who steals the Millennium Puzzle from Yugi Muto. Yugi wins the Puzzle back, but not before meeting Marik through his mind control of Keith, who warns Yugi he will return. In this duel, the methods of the Ghouls is also set: nearly all of the Ghouls cheat in their duels.
When Seto Kaiba organizes the Battle City Tournament (which he did to lure out the Ghouls who had the other two Egyptian God Cards), Marik orders his minions to go to the tournament and defeat the duelists there, hoping to seize many rare cards that the world's best duelists would surely have. However, upon discovering his sister Ishizu Ishtar has given the final God Card Marik needs to Kaiba, Marik travels to Battle City himself to take the card. As it were, Yugi is also in the tournament, giving Marik the perfect opportunity to take both the Millennium Puzzle and the final God Card.
As he travels to Domino, Marik has several other Ghouls attempt to defeat Yugi, including Pandora the Conjurer and the Rare Hunter. But they fail and end up having being sent to Hell as punishment for their failures to defeat Yugi. Marik is desperate enough to duel Yugi himself by controlling Pantomimer using one of his God Cards, the Sky Dragon of Osiris. When Yugi prevails again and takes Osiris, Marik attempts to have two Ghouls named the Masks of Light and Darkness defeat him and Kaiba in a tag-team duel. This too fails, and as Yugi and Kaiba now have enough locator cards to enter the finals, Marik decides there is nothing else to do but face the two himself, and so he and Rishid enter the finals.
After this, the fate of the Ghouls is unknown. It is likely that they are disbanded after Dark Marik's defeat.