Connection
Invader Skoodge is an Irken Invader, who is hated by the Almighty Tallest, like Zim. Zim is Skoodge's best friend, although you probably won't be able to tell, as Zim abuses Skoodge a lot.
Invader Skoodge
Skoodge seems to be unaware that Zim's mission is a lie, or Skoodge doesn't want to tell Zim, as Zim goes crazy whenever he gets upset. Skoodge seems to respect Zim, despite the fact that Zim is more than willing to sacrifice Skoodge to a Hogulus in order to get what he wants. Skoodge, like Zim, seems to be unaware that the Almighty Tallest hate him, even though they shot him through a cannon into the planet Blorch, home of the slaughtering rat people. When Skoodge finds out that the Almighty Tallest hate him, he travels to the planet Earth, and lives in Zim's basement. He was to have a much larger role had the series continued, and was to have helped Zim with his schemes.
Zim
Zim sees Skoodge as a pitiful excuse for an Invader, and calls him gullible, and he seems to be aware that the Almighty Tallest hate him. He often abuses Skoodge, and is not very welcoming when he finds him in his basement. He thinks that Skoodge got lucky when he conquered his assigned planet Blorch, despite Skoodge being an excellent Invader. He is occasionally described as Skoodge's best friend, although he doesn't act like it, as he is quite frequently cruel to Skoodge. He feels that Skoodge is rubbing his victory on Blorch in Zim's face, and his resent for Skoodge increases every time he encounters him.