Invader Skoo is an Irken Invader. His name is very similar to the name Skoodge, another Invader, and the name Spoo, one of Zim's classmates. His character design indicates that he doesn't have a PAK, which is probably simply an animation error since Irkens cannot last more than ten minutes without their PAK. It's unknown what planet he was sent to. His antennae are bent forwards instead of backwards, which is uncommon but not unheard of. He is also one of the many Invaders without stripes on their uniform.