Kamelion is one of Doctor Who’s most criminally underused companions. An experimental animatronic device chosen to try and fill the role the of the Doctor’s erstwhile popular robot dog K9, he appeared as a shape-changing robot severely prone to psychic manipulation. The character turned out to be extremely limited both physically (it hardly ever worked) and in story potential, and his operator passed away, so he didn’t stick around for long — only appearing on screen in two serials during the Fifth Doctor era of Peter Davison, but presumably rattling around unseen in the TARDIS during at least a handful of other stories.
I always thought it would have been interesting if Kamelion had merged with the TARDIS upon his “death,” and perhaps partially repaired the ship’s malfunctioning “chameleon circuit” (which is supposed to help the Doctor blend in any place or time but has, instead, been stuck with the form of a British police phone box since 1963).
Starting today (Jan. 11, 2019), Kamelion is back in a series of three new, full-cast audio adventures from Big Finish Productions to fill in the gap. Davison returns, as does original Kamelion voice artist Jon Culshaw and companions Tegan (Janet Fielding) and Turlough (Mark Strickson), in a series of adventures that will also go on to explore Kamelion’s mysterious origins. Read more about the project here.