Gilad Pellaeon was an imperial from the Thrawn trilogy, created by Timothy Zahn.
In the Legends, Captain Pellaeon was the Grand Admiral Thrawn's second in command.
He was reintroduced in the episode "Family Reunion - and Farewell," the finale of Star Wars Rebels, voiced by Jim Cummings, who also voiced Hondo Ohnaka in Rebels and The Clone Wars.