From Creatures Wikia
The Incubator featured in Creatures 3 is the largest in the series. It is a huge, mechanical pod, and a panel nearby for selecting the type of Creature you wish to hatch. There is one problem with the Creatures 3 Incubator, however. If the player lacks any sprites or there are any other problems with a breed, the Incubator will autokill itself and it will be unrecoverable without using a CAOS command if an egg of the breed is placed inside.