Plo Koon was a Kel Dor Jedi Master and long-term member of the Jedi Council during the Clone Wars.
Background[]
Plo Koon was a Kel Dor from the planet Dorin. This meant oxygen was poisonous to him so he had to wear a breathing mask when on planets with air familiar to humans. He fought at the First Battle of Geonosis and at Cato Neimoidia, where he was killed by Captain Jag after Palpatine issued Order 66.