The Spoffit is a Maxis-made creature that resembles a rabbit/sheep hybrid. It is referenced in many Maxis missions. They seem to be a domesticated non-sapient species; however, in one of the missions (Spoffit Calculator!) they are depicted as showing some intelligence. They are fairly weak creatures.
As of the mission How a Bill Becomes a Law, Spoffits are the official mascot of Spore Galactic Adventures. In certain missions such as Mothership Down, Shenanigan's Fun-Tasy Theme Park, and all of the campaign adventures, Spoffits appear as easter eggs hiding in certain areas or behind buildings and play a bluegrass-type song when zoomed in on. This is because in the first mission you will ever play, Adventure Town, a character named Ms. Spoffit says that some of her pet Spoffits have gotten loose and have ran away. Non-Maxis made adventures created by other players sometimes have Spoffits, and they may well be an interstellar domesticated species.