Carrot

Carrots are a common vegetable found on Earth. Soon after his regeneration, the Doctor found himself craving food and had young Amelia Pond produce different types of foods, most of which he rejected after tasting. He so despised carrots that he rejected them out of hand, without even tasting them. (DW: The Eleventh Hour).

Andy Stone in 2059 was the first of the Bowie Base 1 colonists to become infected by a mysterious life form, most likely through consuming a carrot washed with the base's contaminated Martian water supply. (DW: The Waters of Mars)