Mammal

Mammals were a class of animal. Mammals, or analogues to them, some sentient, appeared on Earth and many other planets. Humans are mammals. (TV: A Good Man Goes to War)

References

The Sixth Doctor stated that "small mammals are quite flavoursome when baked." (TV: The Two Doctors)

On Ravolox, Peri Brown sarcastically referred to "the rustling of small mammals". (TV: The Mysterious Planet)

Vastra claimed that mammals "all look alike." (TV: A Good Man Goes to War)