For a long time now I've been trying to think of a name for the critters that evolve in the Darwin at Home game. There's just one for each player, and it continues to live (however slow-motion) even when you're not playing. Several people have independently mentioned during demos/presentations that it reminded them of Tamagotchi and I've always liked that association.

You have to act quickly when Google says "Your search - tetragotchi - did not match any documents." I suspect that this page will make it give an other answer very soon, but I've already got tetragotchi.com and tetragotchi.org.