What are some cute nicknames like AJ besides AJ?

Well, my sister is having a baby, and she's thinking about naming it Attakin or something like that. It was a cool name. But with a name like that, it's only fair to give him / her a middle name that he can abbreviate. There is already an AJ in our family, so she doesn't want that. What's another kind of abbrebiation you can do with out name. Or maybe middle name that goes with Attakin, that he / she could go by instead?

Thanks :)

-Angel