Xylok

Xylok
Biological type:	Computer-like beings
Appearances:	SJA: Invasion of the Bane SJA: Revenge of the Slitheen SJA: Eye of the Gorgon SJA: Warriors of Kudlak SJA: Whatever Happened to Sarah Jane? SJA: The Lost Boy

The Xylok were computer-like beings, the only example being Mr Smith.

It can only be guessed what the biology and technology of the Xylok is like from the prime example, Mr Smith.