Nien Nunb is a Sullustan male from Sullust, a smuggler and pilot who joined the Alliance to Restore the Republic during the Galactic Civil War. He serves as Lando Calrissian’s co-pilot aboard the Millennium Falcon in the attack on the second Death Star at Endor, in Star Wars: Episode VI Return of the Jedi (1983).
He is one of the great puppet performances in the trilogy — operated by Mike Quinn — and one of its odder linguistic footnotes: the voice was performed by Kipsang Rotich, and the delivery has a naturalism no invented alien language in the film manages.
The character’s longevity is a small mystery of its own. He has perhaps four scenes and no translated dialogue, and he has nonetheless kept turning up for forty years — in the Marvel comics, in the Legends novels as a New Republic officer, in Claudia Gray’s Bloodline, and back in live action with the Resistance in The Force Awakens, at Starkiller Base and finally at Exegol, where he is killed.
What he represents is worth stating plainly. Nien Nunb is the film trilogy’s clearest evidence that the Rebellion is not a human enterprise with alien decoration: the most important shot of the Endor battle is flown by a Sullustan.