Isn't Spinda a panda?
Mermaid: Milotic(?)
Sabre-tooth Tiger: Raikou
Clown: Mr. Mime(?)
Oh. I guess you're right, Mr. Mime is close enough to a clown. But for a mermaid I was thinking more of one that looked more human. And a sabre-tooth that wasn't legendary, maybe it could be a fossil or something.