Zynog
From Tardis Wiki, the free Doctor Who reference
Zynogs were Zygons that were unable to change their form as their original bodyform had been destroyed. This was a punishment for taking the bodyform of another Zygon. Haygoth became a zynog (AUDIO: Death in Blackpool) when he took the form of Patricia Ryder after she died. (AUDIO: The Zygon Who Fell to Earth)
