Complex sentence: The Slitheen are a family of massive, bipedal extraterrestrials from the British science fiction television series "Doctor Who" and are adversaries of the Ninth Doctor and later Sarah Jane Smith.
Split into simpler sentences: The Slitheen are a family of massive, bipedal extraterrestrials from the British science fiction television series "Doctor Who". They are adversaries of the Ninth Doctor and later Sarah Jane Smith.