Penguin Racers, e.g. [1]. Haven't tried it, but it is using penguins. Publisher is apparently Venus Duel Productions. Look at 'old games', though I think they have a wrong screen shot (hiker)
KartRider(R) freely downloadable(though you have to pay for certain features), Windows-only, and focused on online multiplayer.
Kart n' Crazy. Just found a link, unfortunately I can't get the web page of the publisher to work with firefox. So here only a link to a German page describing the game with a few screenshots: [2].
