Sonny (Clara Oswald and the School of Death)

Sonny was the nickname assigned by the Doctor to a Swordfish bar-trophy which he rescued from The Slaughtered Whale, a bar on Earth occupied by Sea Devils disguised as humans. He used the fish to block a barrage of weapons thrown telepathically at him by the creatures, and grew fond of the fish afterwards. Later, he introduced the fish to Clara Oswald, describing it as "our new companion", and as "a character [with] a cutting intellect and a razor-sharp sense of humor". Much to the Doctor's dismay, his new friend did not survive the adventure. (COMIC: Clara Oswald and the School of Death)