Duck

Ducks were a species of bird. People fed bread to them. Hex considered that the life of a duck must be nice and simple. (AUDIO: A Death in the Family)

The Anatosaurus was a species of Dinosaur whose name meant "duck lizard". This was primarily owing to their duck-like beak. However, when travelling back to 80 million years before the 20th century, the Fourth Doctor observed that their behaviour was also duck-like, including spending most of their time in or near water. (PROSE: The Doctor Who Dinosaur Book')

A duck once got into the Doctor's TARDIS, but the Seventh Doctor got it to leave. (TV: Silver Nemesis)

Leadworth had a duck pond which didn't have any ducks, yet Amy Pond still knew that it was a duck pond. (TV: The Eleventh Hour) The Eleventh Doctor later realised that the ducks had been erased from history by cracks in time. (TV: Flesh and Stone)

The Eleventh Doctor, Amy and Rory later had a picnic near a duck pond in New York City's Central Park. (TV: The Angels Take Manhattan)

Clifford Banks resembled a human with a duck's bill. (COMIC: Interstellar Overdrive)

As food
Duck was served as a meal in Chinese restaurants. Elton Pope wanted to enjoy crispy aromatic duck when he invited Ursula Blake for some Chinese at The Golden Locust. (TV: Love & Monsters)

As Rose Tyler recalled, foie gras was made by forcefeeding ducks or geese. She used it as a frame of reference when she learnt that the Slitheen had been harvesting and selling the livers of those who ate at MXQ1. (AUDIO: The Taste of Death)