Mr Smith
From Tardis Wiki, the free Doctor Who reference
Mr Smith was Sarah Jane Smith's computer. The computer was located in the attic of Sarah Jane's house at 13 Bannerman Road. Mr Smith was a super-computer, who had knowledge of every alien race in the galaxy of the 21st century (and possibly, the aliens of the past).
Aliens Featured
True Identity
Mr Smith revealed himself to be an Xylok, and was working against Sarah Jane and her allies. He teamed up with the remaining Slitheen, and helped to kidnap Luke Smith. When a Xylok ship crashed into the Earth in the Distant past, they were all trapped in the planet. When Krakatoa erupted, one Xylok escaped. Decades later, it contacted Sarah Jane Smith through her laptop, where it built itself a body out of machines. (SJA: The Lost Boy)
