Creeper is the your main enemy in the game. The creeper is responsible for killing of most of the human race. The creeper is a blue alien that spreads out from its source(emitter), and will destroy anything it touches after a few seconds.

Creeper pool

Here the creeper is slowly filling the pool


Its is possible to rend an emitter useless by placing a blaster a short distance away from it. The blaster will destroy the creeper instantly meaning the emitter cant spread any.