Scats, sevrerums, five stars, flag tails, frontosas, Jurupari...lots of fish would work.
I think even the right goldfish or two, lots of personality. and they dont stay small.
African Pike (Odoe) it has an amazing personality almost of a dog and they're very easy to care for. They also look alot like a Barracuda x Tiger Fish hybrid
<----- heres what it looks like