Whifferdill

Whifferdill were a shape-changing species from the planet Xenon. (COMIC: Voyager) Their real form was a humanoid, pale yellow in colour with a round, featureless head. (COMIC: The Shape Shifter)

A Whifferdill's shape-changing abilities could be impaired if they were infected with mono-morphia. (COMIC: Genesis!) They were related to Kymbra Chimeras, another shape-shifting species. (COMIC: Changes)

Frobisher, a companion to the Sixth and Seventh Doctors, was a Whifferdill. (COMIC: The Shape Shifter)