Fish
A fish was a variety of water-dwelling animals found on Earth and many other planets.
Some intelligent species seemed to be descended from fish or were at least fish-like in appearance. Example of this were the Aridians, (DW: The Chase) the Fishmen, the Pescatons, (Doctor Who and the Pescatons) the Ockorans, the Kalarians, the Saturnynians, (DW: The Vampires of Venice) the Dax, the Hath (DW: The Doctor's Daughter) and Zargath's race. Damon converted humans into fish people through surgery. (DW: The Underwater Menace)
Examples of non-sentient fish include pilot fish, singing fish, Aaglon sharks, fugora fish, sky fish, and Gumblejack. (DW: The Christmas Invasion, BFA: Neverland, NA: Tragedy Day, BNA: Mean Streets, DW: A Christmas Carol, The Two Doctors)
Fishing, the sport of catching fish, was enjoyed by the Doctor. (DW: The Androids of Tara, The Two Doctors)
Fish was often served with chips on Earth. (DW: The Rebel Flesh)