I recently participated with others for "The Swarm" achievement.
http://www.glitch.com/achievements/player/the_swarm/
"Released a cubimal as part of a 31-cubimal mega-race"
I was a little confused with the word choice of "released" in the description. It bears a similarity to other cubimal-related achievements like "First Series Releaser" and "Second Series Liberator". I was originally under the impression that I would need to set free my cubimal after racing it.