Impossible Creatures expansion on the way

In a somewhat laudable move, Relic Entertainment will be releasing a free modification for its animal-creating strategy title, Impossible Creatures. The expansion, Insect Invasion, will feature 15 new base insects and animals that can be combined with the existing creature library to create a wide variety of new creature designs. The release will also contain new environments and multiplayer maps, as well as nine additional special creature abilities.

Relic has also simultaneously announced plans to release a sample SDK for developers via its Developer Network site, giving users access to updated tools, the game engine itself and a packager to ease the distribution of user modifications.