GIR is Zim's robotic servant who is supposed to act as his SIR unit. but ZIM is still working on duty mode however, he allmost destroyed ZIM.
GIR appears, along with Zim, as the final boss. He was used by Zim in combat against the heroes.
GIR appears as a playable unlockable character. He is one of the Master Models that has to be saved, and one of the few that is playable afterwards. He and Jenny Wakeman are the only unlockable characters playable in both the console and handheld version of the game.
GIR can be unlocked by playing as Rocko in Factory Zone 3, Entry Point 04. In the console version GIR attacks by summoning a giant machine out of his head and slam with it on the ground. In the handheld version he throws taco's instead. His special costume is his Doggy Disguise that he wears most of the time in his show.
GIR appears as a NPC. When entering the Invader Zim level you see GIR walking around with a taco that has the battery inside of it. Zim demands him to put it down, but right on that moment orange goo hits him and takes over his system. GIR then walks away with the taco to Zim's house. He is the boss of the level and controls Zim's house.
When entering the front yard of Zim's house you have to jump over the lasers from the Lawn Gnomes. When you reached the front door you have to rotate the switch, which causes to house to shoot up, and climb the ladder to enter the inside of the house.
Inside you can see the possessed GIR in a machine. You first have to defeat the morphoids. When getting rid of them you must dodge the spikes that will emerge from the ground. You can see where they will emerge because the tiles on the floor begin to shake there. After dodging them you are able to attack GIR. However, after getting rid of some health, you are grabbed and thrown outside again. You then have to defeat, or just ignore, the morphoids that the Robo-parents of Zim shoot at you. You then repeat the same process as before when you reach Zim's door.
When thrown outside again both the Lawn Gnomes and the Robo-parents will do what they previously did. When reaching Zim's door again repeat the same process and defeat GIR. After his defeat GIR returns back to normal.
Zim appears as a playable character. He drives along with GIR in the Voot Cruiser.
GIR appears as a main non-playable character in Nicktoons MLB. He is the announcer of the games along with Perch Perkins. But instead of giving comments, and normal responses he just shouts out random things.