I'd say about a third of all Miis are of "indeterminate gender" while another third are probably better labeled as "indeterminate species." I've run into some goofy-looking Miis, but it's the low-effort ones that give me added incentive to win. If a person couldn't even put in the entire five minutes to design their Mii, then they need a two-turnip trouncing.
Not sure how I would feel if I ran across a Doogenheimer, but I'll be moving to Georgia soon, so I imagine there's a (very) slim chance I might come across one online hailing from Alabama in the near future.