A Dalek is among Doctor Who's most feared enemies. He has battled them during every phase of his life. The Daleks forever strive to become the dominant beings in the universe, eradicating everyone and everything that is not "Dalek."
The Daleks--one of two main lifeforms from the planet Skaro--are the result of some very frightening experiments done by a considerably "mad scientist." Highly intelligent but highly unstable at the same time, the creator of these evil beings realized that the wild and sometimes volatile nature of his creations could be problematic if not dealt with speedily, and therefore had the Dalek creatures encased in special mobile armor suits that act as both a vehicle and battle machine for the creatures. They are armed with a laser ray, an arm with a plunger at its end and can only see through a long stalk in the middle of their heads. Also, since Daleks are part machine, they talk like a robot talks. Their battle cry is "EXTERMINATE!"