Whale

Whales were a group of Earth marine mammals. They ate krill.

The Doctor's TARDIS took on the shape of a whale, both internally and externally, when Nyssa repaired the chameleon circuit. By projecting the Fifth Doctor's heartbeat, they were able to entice whales in. (ST: The Deep)

In a possible future, Haemovores sometimes ganged together to hunt whales. (MA: Goth Opera)

Star Whales were space-born creatures which resembled whales. (DW: The Beast Below)