Aurra Sing is a Palliduvan bounty hunter and sniper, first seen as a non-speaking spectator at the Boonta Eve podrace in The Phantom Menace (1999), where she was performed by the model Michonne Bourriague. StarWars.com describes her as "a feared bounty hunter known for her chalk-white skin and built-in comlink antenna", an expert sniper "who would work for anyone who paid her".
Built entirely out of a crowd shot
She is the definitive example of Star Wars' habit of promoting extras. A pale figure with a head-mounted antenna appears in the stands for a handful of frames, gets an action figure, accumulates a Legends biography through the 2000s, and is eventually rebuilt from scratch for The Clone Wars, voiced by Jaime King.
Fett's first mentor
Her most consequential canon role is as the person who trains Boba Fett after Jango's death — and then abandons him on Florrum the moment Jedi appear. It is a precise piece of writing: the boy's introduction to the profession is being taught by someone who demonstrates, practically, that loyalty is not part of the arrangement.
Coruscant and after
She is imprisoned for an attempt on Padmé Amidala's life and later joins Cad Bane's raid on the Senate Building — the hostage operation that also introduced Bane. The two of them together form the animated series' core professional partnership, and the show is careful never to make either of them redeemable.