K9 (The Choice)

A version of K9 travelled with the Mistress in Ecto-Space. It was unclear how he was related to other K9 models in the normal universe. (AUDIO: The Choice, The Search)

Behind the scenes
This version of K9 — divorced from any explicit ties to a televised version — was created to give BBV Productions clear access to those elements of K9 wholly owned by Dave Martin and Bob Baker.

It was implied that version of K9 was in fact K9 Mark II, who had remained in E-Space with Romana II after the events of TV: Warriors' Gate while the Mistress was implied to be Romana herself.