Big Five

The Big Five are five board members of Kaiba Corp in the anime Yu-Gi-Oh. Their names are Gansley, Crump, Johnson, Nesbitt, and Lector. Gansley is the leader and founder of the Big Five who started his business career from a lemonade stand that he stole from his neighbor. Crump is an accountant who is obsessed with penguins. Johnson is a legal expert and judge who sets people up (at one point convincing a jury that a man who was afraid of water stole a boat). Nesbitt is the techno geek and a nerd who wanted to make machines for war. Lector is the former vice president of Kaiba Corp and the best duelist.

Pegasus arc
When Kaiba left Kaiba Corp after being defeated by Yugi, the Big Five conspired with Maximillion Pegasus to take over Kaiba Corp, and have Kaiba killed. Kaiba survived, however, but Pegasus defeated him in a duel and trapped his soul inside a card. The Big Five watched the duel between Yugi and Pegasus, planning to broadcast it if Pegasus won. However, Yugi won instead.

Virtual World
Upon return to Kaiba Corp, Kaiba fired the Big Five, but they told him they were pretending to work for Pegasus. They also finished Kaiba's virtual reality game, so he entered it, but they set a trap inside it for him to kill him. Kaiba's brother Mokuba asked Yugi and his friends to help. Soon, Yugi, Kaiba, Joey, and Mai faced off against the Mythic Dragon, which the Big Five themselves seemed to take the form of (a five-headed dragon). Joey, Mai, and Mokuba were all killed by the Mythic Dragon (later to be revived by Mystical Elf), and Kaiba and Yugi worked together to summon Master of Dragon Soldier, which destroyed Mythic Dragon, trapping the Big Five in the virtual world.

Noah arc
The Big Five remained trapped in the virtual world so long that their bodies were destroyed. They soon came across Noah, the son of Kaiba's wicked stepfather Gozaburo, and joined forces with him as they shared a common enemy in Kaiba. When Yugi, Joey, Téa, Tristan, Serenity, Duke, Kaiba, and Mokuba entered the virtual world, Noah and the Big Five separated them for the Big Five to duel them and steal their bodies. They dueled using a deck master system, with the Big Five in the forms of their own deck masters. Gansley was Deep Sea Warrior, Crump was Nightmare Penguin, Johnson was Judge Man, Nesbitt was Robotic Knight, and Lector was Jinzo.

Yugi defeated Gansley, Téa defeated Crump, and Joey defeated Johnson. Tristan, Duke, and Serenity dueled Nesbitt at once. Although they were able to defeat him when Serenity attacked him, Tristan's life points went down to zero during the duel, so Nesbitt stole his body and digitized him into a robot monkey. Kaiba defeated Lector. Nesbitt kidnapped Mokuba and took him to Noah to brainwash him.

Gansley, Crump, Johnson, and Lector returned to chase Joey, Duke, and Serenity and steal their bodies. Crump and Lector got in a fight over who gets to choose first. Noah, however, recalled them and chastised them for cheating. He then sent them to duel Yugi, all in Tristan's body. They dueled Joey, taking it in turns to possess Tristan's body to duel, rotating their deck masters as well. Lector did most of the duel, but they were defeated when their deck master was destroyed. Again, they tried to steal the gang's bodies by force, but Noah recalled them again, and permanently trapped them each in an isolated corner of the virtual world.

The Big Five were never seen again following their imprisonment, but did not remain there forever; they were killed when Noah blew up the fortress that the virtual world was stationed in, deleting the virtual world and anyone in it at the time, including Noah and Gozaburo themselves.

Trivia

 * Two of the Big Five, Johnson and Crump, share their names with the only two X-Nauts from Paper Mario: The Thousand-Year Door who have names. Lord Crump is the general of the X-Nauts (and, like Crump of the Big Five, is fat), and Johnson is a regular X-Naut referred to once by Crump.
 * Lector takes the form of Jinzo in the virtual world. Jinzo's mask resembles that of Hannibal Lecter, which may be where Lector gets his name.