Voiced by: Richard Steven Horvitz
A villain with a bird fixation, Aviarius is actually an arch-foe of Team Go. He wears a caped costume with bird-foot-like boots and speaks in an over-the-top, villainous cackle. He has under his command a number of bird-themed weapons, such as flocks of hummingbird-shaped homing missiles and a gigantic robotic flamingo. Voiced by Richard Steven Horvitz.