Mouse

A mouse was a species of mammal native to Earth and other parts of the universe.

On Gallifrey, a mouse was enlarged by the Rani during an experiment and ate the Lord President's pet cat. (DW: The Mark of the Rani)

In the year 4000, Froyn and Rhynmal intended to test their new long-range teleportation system by sending two lab mice to Mira. (DW: The Daleks' Master Plan)

The Doctor occasionally carried a toy mouse. (DW: The Talons of Weng-Chiang, The Doctor's Daughter)

The Doctor claimed that there was a planet which had talking mice. (NSA: Winner Takes All)