The 14-year-old Chinese crested and Chihuahua mix won the honor Friday night at the 23rd annual contest at the Sonoma Marin Fair.
Owner Terry Schumacher of Hanford, California, says the 2-pound (900-gram) dog has come a long way since she was found abandoned behind an apartment building. Schumacher says she first thought the pooch was a rat.
Yoda's distinction comes a year after a one-eyed Chihuahua named Princess Abby claimed victory. A pedigree Chinese crested won in 2008 and another Chinese crested and Chihuahua mix was the ugliest in 2007.
In past years, the winner's owner has received a $1,000 check.