Bulb

Referred to as simply an alien ‘Bulb’ by the Doctor, the bulb had burrowed underground on a French farm where it had feasted on the soils nutrients growing to a huge size. Its strong powerful roots were able to drill through the soil and attack those above ground and pull them under. The bulb was shrunk by a particularly bad batch of Michel’s wine belonging to farmers Alain and Simone. Shrunk to a more portable size the Doctor removes the bulb to be rehoused elsewhere, somewhere out of the way. (DWAM: The Mutant Turnip)