Creepers are dangerous mobs that are bound to explode when seen in Survival Mode. When they see you, they run for you. When a creeper gets near you, it will turn white and green. It is ready to explode. You just need to run away from the area that the creeper is in. If you kill a creeper, it may drop Gunpowder or a Music Disc. To see about Charged Creepers, click here.