You were a Kid That Lived a Normal Life, One Day you were talking a nice walk, and you fall into a sewer, getting knocked out! You wake up and find yourself waking up outside of Zim’s Base Of Operations (its just his house pretty much), and you decide to knock on the door.

you see a green dog, well something in a green dog disguise, tinier then you, its a pretty bad disguise, there is a visable zipper from the costume, and its standing on 2 legs

Gir: “HI!” the thing says at a loud volume, you dont understand why its so loud, but you explain you need a home, and because GIR thinks You’re a, and i quote, “cute human”, he cries to zim for a while, and due to the annoyance, and it would give zim a better idea of learning what humans do, (due to the fact he wants to take over the world, he needs to learn about humans), So they Adopt you i guess? so he reluctantly agrees, and GIR leads you inside the house.