Whifferdill
From Tardis Wiki, the free Doctor Who reference
Whifferdill were a shape-changing species from the planet Xenon. Their real form was a Humanoid, pale yellow in colour with a round, featureless heads. (DWM: The Shape Shifter) Their shape changing abilities could be stopped if they were infected with Mono-Morphia. (DWM: Genesis!) They were related to Kymbra Chimeras, another shape shifting species.. (DWM: Changes) Frobisher was a Whifferdill, he developed mono-morphia for some time. (DWM: Genesis!)