Judges in California named the Chinese-crested Chihuahau the winner of the competition at the Sonoma-Marin Fair.
Owner Terry Schumacher says that the first time she encountered the tiny dog behind an apartment building in America, she ran away, thinking that it was a large rat. But when she returned, she realised that it was in fact a dog.
She took in the pooch, which weighs less than a kilogramme, and named it after the Jedi master from the Star Wars.
Other finalists of all shapes and sizes were missing limbs and eyes. The World's Ugliest Dog competition helps to raise awareness around rescue dogs.