Cool, whatever you want.
Top 10 most forgotten Mario characters
2. Metal Luigi
3. Bronze Luigi
4. Purple Luigi
5. Green Mario Luigi
6. Mr. L
7. Cat Luigi
8. Tanooki Luigi
9. Tall, skinny Luigi
10. Shadow Luigi
If you go to the list of given avatars, there is a selection called AC Characters. There's a cute Rover one in there.
Fun fact: I was gonna get Pokemon Sun but my 2D card was 2 gigs (instead of 4 like what a typical New 3DS should have. What the heck, Amazon?)
You do have to have less than 10 villagers to adopt one, but just asking couldn't hurt!
I'd post in the Looking For thread in the Villager Trading Plaza and say you're looking for Bob. I'm sure someone on here has him!