Oyster

An oyster was a type of sea creature on Earth that could produce pearls.

The Third Doctor quoted from The Walrus and the Carpenter, comparing Stephen Le Page and the Perseus Corporeals to the walrus and the carpenter, and humanity to the oysters. (PROSE: /Carpenter/Butterfly/Baronet)

The Molluscari were described by the Eighth Doctor as "aggressive space oysters". (AUDIO: Orbis)

Brain parasites were considered a delicacy on some worlds, tasting like oysters. Jack Harkness knew this because at one point in his life he had been forced to eat one to be polite. (TV: Immortal Sins)

Bernice Summerfield and Mushtaq Anson had oysters and wine before Leo Didas arrived at the Braxiatel Collection. (PROSE: The Price of Everything)