Shapeshifter (The Upper Deck)

Shapeshifters were creatures capable of changing their appearance. They often targeted developed worlds assuming a shape that would allow them to feed on creatures fooled by its appearance. One, found by the Doctor in London in 1959, had taken the form of a double-decker open backed bus. Its disguised form enabled humans to walk onboard where they were trapped to be digested later. The passengers were allowed to leave only after the Doctor had stunned the creature by shocking its nervous system using his Sonic screwdriver. The creature was contained and the Doctor left to take it to the Elliptical Zoo on Vatrama lll. (DWAM: The Upper Deck)