K9 is a mobile computer in the form of a dog. He was for many years the constant companion of the renegade Time Lord known as The Doctor, though the original K-9 eventually parted company with him, to be succeeded by a separate and distinct K-9 MK II (who later also left). A third K-9 was given by the Doctor as a gift to Sarah Jane Smith.
Powers and Abilities
Tends to get stuck in narrow doorways
Blaster attachment in snout
The K9 who appeared in the Marvel Comics Doctor Who series was the MK II version, seen in the TV series between 1978-1981.
The version of K-9 seen in the Marvel strip was often drawn as much smaller than his TV counterpart so that the Doctor could carry him.