Watto is a Toydarian junk dealer in Mos Espa on Tatooine who owns Shmi Skywalker and her son Anakin at the start of The Phantom Menace (1999). Andy Secombe voices him.
The slaveholder
It is worth stating the fact the film treats lightly: Watto is a slave owner, and the plot of the first act is a negotiation over a child's freedom conducted as a bet on a podrace. He wagers Anakin's liberty on Sebulba winning, loses, and hands the boy over — while keeping Shmi, which is the detail that sets up Attack of the Clones' entire Tusken massacre sequence.
Mind tricks don't work on me
His scene with Qui-Gon Jinn establishes, in about four seconds, that the Force's most convenient power has limits — Toydarians are simply resistant to it. It is a small piece of worldbuilding that the franchise has leaned on ever since whenever a plot needs a character who cannot be talked around.
Afterwards
By Attack of the Clones he has sold Shmi to a moisture farmer, Cliegg Lars, who freed and married her. He recognises the grown Anakin, gets no acknowledgement worth having, and that is the last the films see of him. He recurs in The Clone Wars.