Before I start ... hey, Vinnie, I know a Neopet when I see one ...
Let's see ... if I were an imaginery friend ... I think I'd look either like Sully in "Monsters, Inc." (only a chick version) *OR* like the hippo in "Madagascar". Bottom line ... something incredibly feminine, yet quite large, with unrealized personal strength used for quieting down unruly boys when they need it (hopefully, not breaking any necks). My kid would be a girl who maybe doesn't have a Mom and needs a protective female presence. Yes, that's it.
And my name would be Nana.
There you have it.