A doogle sardine is a quest item used in the Gertrude's Catquest, which when completed, allows players to obtain a pet cat. It is made by using doogle leaves on a raw sardine. During the quest, a Doogle sardine is given to Fluffs, the mother of all player-owned cats. A player cannot feed it to their own pet kitten, as this simply gives the message 'Nothing interesting happens.'
Because this item cannot be fed to player-owned cats, cannot be fed to Fluffs after the quest, cannot be traded and cannot be reverted back to a raw sardine, it is considered a useless item after the quest and it is recommended that players do not make more.