Krynoids were a violent carnivorous alien plant species bent on consuming all plant-eating animals. In The Seeds of Doom (1976), two Krynoid pods were discovered in an Antarctic base after laying dormant for 20,000 years. The first pod was thawed out and infected scientist Charles Winlett, prompting the Fourth Doctor (Tom Baker) to investigate. The second pod was stolen, infected another scientist and grew to the size of Chase Mansion. The Krynoid was eventually destroyed by UNIT.
Information surrounding the Krynoids and a pod are still held in the Black Archives.
Inspired by The Day of the Triffids and The Thing From Another World, this six-part serial was written by the late Robert Banks Stewart (1931-2016) who also introduced another shape-shifting race in Terror of the Zygons (1975).