Debut -- Gingerbread (Season 3)
Died Same Episode
Mr. Sanderson's the first vamp that Joyce recognizes when she's come to watch Buffy in action. She recognizes him from the bank, where I guess he had his day job...um, when he had a day job, that is. Apparently he was nabbed after hours. His Vamp Dress Comparison puts him in a blue striped shirt, tie, jacket and pants. And he sports a day-job-banker-guy hairdo. Yes, that is vague.
Anyhoo, after Sanderson jumps out of the bushes, startling both Buffy and her mom, he takes off. But Buffy catches up to him and is able to stake him. It kinda looked like Buffy was lying on the ground as she staked him, and Sanderson could only groan in dismay. He spoke not. Guess he wasn't a teller. (I had to say it.)