Well, one pair of cats and their offspring can produce more than 400,000 kittens in under 10 years.
In 1970 a Burmese cat called Tarawood Antigone, in Oxfordshire, UK, gave birth to 19 kittens. 14 males and 1 female survived. The Burmese have the highest average birthrate at around 5 kittens per litter.
Dusty, a tabby from Texas, gave birth to 420 kittens in the course of her lifetime.