GIR (G Information Retrieval Unit) is the deuteragonist of Invader Zim, and the secondary antagonist of the Netflix movie Invader Zim: Enter the Florpus.
He is the hyperactive robotic assistant of Zim and the closest friend Zim has :) Yes, I took this from the wiki AND corrected it, GIR and Zim ARE FRIENDS.
GIR's usual Earth disguise consists of a green "mongoose-dog" suit with a zipper on the stomach, and a head that can be pulled over like a hood.
GIR is happy-go-lucky, enthusiastic, energetic, excitable, and extremely hyperactive, and will eat just about anything, regardless of whether it is edible or not.
GIR does not hate or dislike anyone, and can at times appear friendly with Gaz and Dib.