An oyster was a type of sea creature on Earth which fed by filter-feeding. (PROSE: Autaia Pipipi Pia [+]Error: Code 2 - no data stored in variables, cache or SMW.) Oysters could be found on other planets too, such as Slarvia. (COMIC: Bloodsport [+]Mark Wright, DWM Comics (Panini Comics, 2016).)
When an oyster got something stuck between its mantle and its shell that caused it pain, it secreted a substance that hardened over it, creating a pearl. (PROSE: The Feast of the Drowned [+]Stephen Cole, BBC New Series Adventures (BBC Books, 2006).)
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 [+]Error: Code 2 - no data stored in variables, cache or SMW.)
The Molluscari were described by the Eighth Doctor as "aggressive space oysters". (AUDIO: Orbis [+]Alan Barnes and Nicholas Briggs, Eighth Doctor Adventures (Big Finish Productions, 2009).)
Brainspawn 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 [+]Jane Espenson, Torchwood series 4 (Starz, 2011).)
Thanks to Chef Bandit, Jeff Morris was once able to prepare, for his girlfriend, sheered scallops, monk fish, and oyster sauce linguini, finished off with a vegan "heritage" cheese gourd. (AUDIO: Cardiff Unknown - October 2018 [+]Error: Code 2 - no data stored in variables, cache or SMW.)
Bernice Summerfield and Mushtaq Anson had oysters and wine before Leo Didas arrived at the Braxiatel Collection. (PROSE: The Price of Everything [+]Error: Code 2 - no data stored in variables, cache or SMW.)