Orca whale...
So I could kick everyones Butt.
Ok so its not a fish... sue me.
I'd be a sea turtle.
Oh, wait, that's not a fish, either!
Technically you could argue that since the group "fish" is not monophyletic, Orca and turtles could be considered highly derived "fish".
And in that case, I'd be an Elephant, because that'd be fun.