|Powers and Abilities||Mutant|
Thunderbird is a mutant.
Little is known about the man known as Thunderbird. Given his outfit, he appears to be of Native American origin.
Thunderbird was unnamed and unvoiced.
The series never specifies whether it was John or James Proudstar who is Thunderbird.
Thunderbird was originally going to die in "Night of the Sentinels, Part Two" instead of Morph. This follows the original comics where Thunderbird died on his second mission for the X-Men. However, it was pointed out that the writers were going to kill off their only Native American character right away. The character of Morph was then created, loosely based of deceased character Kevin Sydney while Thunderbird was reduced to a cameo. Wolverine's friendship with Morph does reflect his comic book friendship with Thunderbird.
Although he appears in the opening credits as a member of Magneto's Brotherhood of Mutants, he never has any association with the team in the series itself or comics. His inclusion was due to Larry Houston and Will Meugniot. When they created the credits they had a problem with the final charge since there were more X-Men than villains. They included Thunderbird, and the unnamed grey mutant incorrectly thought to be Gargoyle, to bring Balance to Magneto's side. They used those characters because "Slave Island" was finished enough to have the models.
In the Comics
John and James are brothers from the Apache Native American tribe.
John' powers are superhuman senses, strength, speed, stamina, and sturdiness. James has similar powers.
John was drafted into the Vietnam War into the Marines.
On the team's second mission, John leapt onto a plane against Professor X's orders to stop the fleeing enemy. The plane exploded kiling him, and it was later discovered that the enemy survived.
James took John's body and gave him a warriors funeral in accordance with their tribal traditions.
James blamed the X-Men for his brother's death. He was recruited by Emma Frost to fight the X-Men along with her Hellions. Emma did not feel they were ready to take on the X-Men but James defied orders to fight them. He took his brother's costume and name to lead the X-Men to where his brother died. When given the opportunity to kill Xavier, James relents and makes peace with the X-Men. Xavier offers him a membership but he declines to stay with the Hellions.
Cable makes him the same offer months later but again turns it down. Afterwards, he finds his entire tribe murdered and believes that the Hellions did it to punish him for leaving the team.
James joins the X-Men subgroup New Mutants, who then cut ties to the X-Men, to get revenge against the Hellions. At this time he changes his name to Warpath. During this time the team fights Toad's Brotherhood of Mutants. He eventually confronts Frost who tells him she wasn't involved in the tribe's murder.