A cat in Scotland reportedly killed nearly 30,000 mice in its lifetime.

The cat, by the name of Towser, lived in the Glenturret Distillery in a Scottish town by the same name. Distilleries often keep cats on their premises because mice like to eat the barley that is used for making whiskey.

In Towser's 24 years of service, she caught a total of 28,899 mice, which is a Guinness World Record. That's an average of about four mice a day! After her death in 1987 they erected a bronze statue in her honor.
(Sources: 1, 2)