... a young man with skin that is yellowing into old parchment. He's wearing a World War Two leather pilot's cap and dark goggles and carrying a pack. In spite of his youth, he carries himself like Old China as he walks toward the entrance with the gait of an old man ...

Fancher and Peoples

He's a genetic designer for Tyrell Corporation. A boy genius. He graduated twice in genetic engineering. So good in his work that he represented a menace to Tyrell Corp. So Eldon Tyrell infected Sebastian with a virus that caused him to grow old before his time. Tyrell promised to cure him if he accepted to work for the Corporation.

A fast-aging lonely guy who falls for Pris' act. Sebastian derives pleasure from entertaining the beautiful replicant. Pris' helpless approach gains Sebastian's confidence and gets the replicants closer to finding Tyrell. Batty uses Tyrell's obsession with beating Sebastian at chess to demand longer life.

Played by actor William Senderson. Other works by Senderson were: Savage Weekend, Raggedy Man, Lonesome Dave, The Firm and the TV series Newhart. Regarding Sebastian, Sanderson created him by taking a lot of elements as starting points. One was Einstein's physical image. "I was thinking about Sebastian as a genius, so I referred to Einstein. I also watched a documentary about a kid affected by the progeria syndrome. This child was walking as if his heel were aching, so I recovered that gait."