Lynx (Cat's Cradle: Time's Crucible)
From Tardis Wiki, the free Doctor Who reference
Lynx was a cat generated by the Doctor's 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 ruled by a being known as the Process, to which they had been brought from 1991 London. (NA: Cat's Cradle: Time's Crucible)
He next followed the Doctor to New York City 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)
