The womp rat is a large, omnivorous rodent native to Tatooine. It is widely considered to be a pest. They are slightly larger than two meters in size. There were two races of womp rats: ones that lives in Beggar's Canyon and ones that lived in the Jundland Wastes. While they are opportunists and are extreemly fond of carrion and refuse, they are also predators. Their normal prey includes small animals, such as profoggs.
Womp rats travel in packs to overwhelm their prey. These packs can consist of up to 20 individuals. When they bite, the teeth of womp rats set in and the animals would not release, even if they were killed; Owen Lars had seen a bantha with a dessicated womp rat skull still biting down on it.
The Beggar's Canyon womp rat reproduce at an alarming rate. Once it reproduced to such a point that the population could not be kept in check, and womp rats were hunting Jawas and raiding storehouses. The Imperial prefect of Tatooine then allowed people to hunt them at ten credits per rat. Luke Skywalker and his friend Biggs Darklighter got enough womp rats to upgrade their T-16 Skyhoppers and to have enough money for the Academy.
The Jundland Waste womp rat appeared shortly after Imperials arrived on Tatooine, and some have speculated it was a mutated form of the Beggar's Canyon womp rat, affected by chemicals from Imperial waste dumps. They were lesser in number and did not reproduce as quickly as the Beggar's Canyon womp rat.
Another variety, the swamp womp rat, was found on a few fringe worlds as well as on Cularin.
It was not unheard of for people to have domesticated womp rats as pets.
Luke Skywalker and his friends, including Biggs Darklighter, used to "bullseye" womp rats while flying T-16 Skyhoppers with stun blasts for fun and for target practice.