Glad to hear! Character sheets should go in the OOC, and then transferred when they're accepted. If you'd like to be the Andalite, PM me (Since, in retrospect, the CS doesn't work for aliens).

As for physical variations, I think they have different colored/patterned fur. [url=http://animorphs.wikia.com/wiki/Andalite]The wiki knows more than me, though.[/url]