Watto was a Toydarian junk dealer in Mos Espa who bought Shmi Skywalker and her son Anakin from Gardulla the Hutt. An inveterate gambler, he sponsored Anakin in several Podraces, but often bet against his own slave, who was talented but inexperienced.
Watto lost Anakin to Qui-Gon Jinn in a wager on the Boonta Eve race. Years later, he sold Shmi to the moisture farmer Cliegg Lars.
Anakin Skywalker was a slave belonging to Watto. Watto put the boy to work in his junk shop, repairing machinery, and occasionally racing Pods.
Watto was also the owner of Shmi Skywalker, who helped maintain technology in Watto's shop. Moisture farmer Cliegg Lars freed Shmi from slavery and married her.
Watto runs one of the larger junk shops in Mos Espa. Though he can't stand the heat and flies on Tatooine, he makes a decent enough living to tough it out.
Qui-Gon Jinn attempted to haggle with Watto for needed hyperdrive parts to repair the Queen's starship. As Qui-Gon discovered, Watto was immune to Jedi Mind Tricks.
Watto bet heavily on racing champ Sebulba for the Boonta Eve Classic Podrace, confident that "he always wins!" The Toydarian junk dealer lost everything in the wager.