It used to be that you called any mixed-breed dog a mutt. But at today’s dog parks, you’re just as likely to run into schnugs, bassadors, and dalmadoodles. Also, if someone has a suntan, you might say he’s brown as a berry. But...
A whole nother may feel right to say, at least informally, and you will find it in dictionaries, but it’s better to avoid it in formal writing and speech. This is part of a complete episode.