Whifferdill
From Tardis Wiki, the free Doctor Who reference
Whifferdill were a shape-changing species from the planet Xenon. (DWM: Voyager) Their real form was a Humanoid, pale yellow in colour with a round, featureless head. (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, but he developed mono-morphia for some time. (DWM: Genesis!)
powers and abilities
whifferdills had similar shapeshifting abilities to the kymbra chimera, anothershapeshifting race related to them. They could turn into any species they desired.