I actually made this work in a recent cheesy short campaign. My character was an intelligent monkey, although he was still an animal and couldn’t speak. After meeting the party, he decided to go do his own thing, which just so happened to be the same thing as the rest of the party.

It worked out really well. The rest of the party could navigate social challenges without having to explain the monkey, I could sneak around and grab MacGuffins without having to accommodate huge humans who were terrible at climbing.

I doubt it works well for longer or more serious games, but it matched the hectic nature of the campaign and led to some hilarious moments.