Pigma is an exceptionally greedy miser who does not care who he hurts so long as he ends up with a large paycheck in the end.
Although Pigma's first appearance was in the unreleased Star Fox 2, he did not make his first official appearance until Star Fox 64. Pigma is most recognized in Star Fox 64 because he put high-pitched emphasis on the word "real." Pigma was one of the original members of the first Star Fox team, headed by James McCloud. After the scientist Andross' exile to Venom, the team was sent to investigate strange activity coming from the planet. Upon their arrival, Pigma's greed caused him to commit treason against Corneria by betraying the Star Fox Team to join Andross. Only Peppy Hare managed to escape. He was later hired to fly for Star Wolf, in which he focused his attacks on Peppy, his former teammate.
In Star Fox: Assault, it was revealed that Wolf O'Donnell later expelled Pigma from Star Wolf due to his incredible greed and distrustful nature (which might explain the claw marks Pigma now has on his head). After the initial of the Aparoid invasion, he hid away in the military base on Katina (occupied by Aparoids), sending distress beacons which the Star Fox Team soon picked up. After the Katina Base is cleansed of Aparoids, Pigma swoops by and steals the Core Memory from a large Aparoid, believing it will make him rich. In an interplanetary game of chicken, the Star Fox Team invades the Sargasso Region (where they thought Pigma usually hangs out). Just before they succeed, the Star Wolf team enters the scene. After a short dogfight, Wolf reveals that Pigma is no longer part of Star Wolf, but his teammate, Panther, points in the direction where Pigma may be heading. The Star Fox team makes way for Fichina. Once there, they discover that Pigma has deactivated the Climate Control Center, making Fichina a snowy wasteland. Upon investigating, they also find out that Pigma is leading the Aparoids somehow. As they eliminate the Aparoids from Fichina and restore the Climate Control Center, they uncover another clue leading to the Meteo asteroid field. Meanwhile in his ship, Pigma has a nightmare about being assimilated by the aparoids, in which he talks in his sleep (notice how during the cutscene, Pigma's voice deepens when the Aparoids are in control), wakes up briefly and ponders over it, and then falls asleep again. Once the Star Fox team gets through the Asteroid field, they finally catch up with Pigma. However, in a last ditch effort to avoid capture, Pigma ultimately undergoes assimilation. Pigma is seen being fused with a seemingly inactive Aparoid spacecraft. He is later transformed in what appears to be an enormous, Aparoid-mutilated face with the spacecraft as its hull and shielding with mechanical, six tentacle-like arms with claws on the end as weapons and bomb launchers circling his face, similar to the Gorgon. Eventually, the machine is destroyed by Star Fox, supposedly killing Pigma in the process. However it is not certain if Pigma was actually aware of what was happening around him at the time and if it was actually him that Star Fox confronted, or if Pigma's mind was already taken over. As Fox said just before the fight, "He can hear us, but he's not listening". But since he survived in Command, it was probably just a decoy.
Pigma makes a subsequent appearance in Star Fox Command. His body remains transformed in the shape of a cube-shaped puzzle box cyborg. He can be encountered as a final boss in Sector X and Sector Y. It is revealed that Pigma wanted Star Wolf to bring Star Fox to him, and that the plan to get them there was made by Krystal. Pigma explains that he spared Star Wolf because he found them to be good friends. Pigma also commands some Anglar forces to destroy Star Fox, but he shows up himself after they are defeated. Pigma is then destroyed, which leads to one of two endings (where Falco creates Star Falco or Fox and Falco retire and join the G-Zero Grand Prix).
Pigma appears in Super Smash Bros. Brawl as a sticker. He raises arm attack power by seven.
As Shigeru Miyamoto states in issue 98 of Nintendo Power magazine, in the Japanese version of Star Fox 64, "Pigma speaks in the Kansai dialect of Japan. In Kansai, people end their sentences with the word 'dengar.' So, it's sort of a Japanese joke."