Lynx (Cat's Cradle: Time's Crucible)
From Tardis Wiki, the free Doctor Who reference
Lynx was a cat generatated by the Tardis, he was a projection that followed the Seventh Doctor and Ace through space and time on three accounts. Firstly he followed them to a Wasteland were a being known as the process. Which they had been brought to from 1991 London. (NA: Cat's Cradle: Time's Curcible)
He next followed the Doctor to New York in the year 2009. (NA: Cat's Cradle: Warhead
He finally entered the Tardis after the Doctor and Ace had visited the world of Tír na n-Óg. (NA: Cat's Cradle: Witch Mark)
