Chiron's Wheelchair is the magical wheelchair which Chiron, a centaur, uses to disguise himself as a physically impaired human. Percy Jackson always wonders how he could get his backside into the wheelchair. He has come to the conclusion that the wheelchair was magical like the Hunters' backpacks, which are enchanted to hold numerous items.
Chiron uses his wheelchair to hide his horse body so he could be Percy's Latin teacher, using the name "Mr. Brunner" while at Yancy Academy. He stays in the wheelchair for most of his tenure at the school, only exiting the chair when he is alone with Grover Underwood. He is also seen using his chair at Camp Half-Blood while playing pinochle with Mr. D. He eventually leaves the wheelchair to show Percy his true form and show him around the camp.
Chiron was confined to his chair because he was injured during the Battle of the Labyrinth.
When talking to Jason Grace, Chiron goes back in his wheelchair.
When talking with Meg McCaffrey and Apollo, who was turned into a human, Chiron sits in his wheelchair. However, his regular fake legs were replaced with legs of a lady as a prank from the campers of the Hermes' Cabin.
Percy Jackson (Film Series)
In the film, Chiron is seen in his wheelchair during the first part of the movie, up until Grover Underwood and Percy leave the museum. The next time they see him, he is in full centaur form. The wheelchair is never seen without Chiron in it in the film, although before the Capture the Flag game, Luke quips to Chiron that Percy, who does not have a helmet at the time, will probably need the wheelchair.