Sam Guevenne is a drunkard who challenges Crotch Guzzler to a drinking contest. His real identity is the Daedric Prince Sanguine.
Story
Crotch Guzzler was disappointed with last episode's sexy party, as he was only allowed one drink. He goes to the Bannered Mare, determined to have more than one drink. Here he meets Sam Guevenne (or Sam Guenvere, he can't tell), who states that Crotc looks like someone who could hold his liquor, and offers a staff as the prize if Crotch can outdrink him. Crotch decides he needs to drink until Sam's name makes sense. Sam hits his limit after one drink, and Crotch barely makes it past two, after which he blacks out.
Crotch wakes up in Markarth in the Temple of Dibella. Asking around, Crotch goes to Rorikstead and is eventually able to trace back what happened "last night" to a woman named Ysolda.
Speaking to Ysolda, Crotch discovers that he got engaged on his wild night out with Sam. He immediately decides to intimidate her into telling him what else he said - that the ceremony would be in a castle, Morvunskar, and that Sam was to be the best man.
After arriving at Morvunskar and meeting some people who happily ran into their own traps and hearing the voice of an obnoxious daedric prince, he enters a portal labelled 'Misty Grove', where he finds a party of clones, and Sam. Sam states that Crotch is not likely to have remembered his first trip to the misty grove, and that he definitely earned the staff he had promised - at which point he reveals himself to be Sanguine/Darth Maul, the daedric prince of debauchery. After receiving the staff, he is teleported back to the Bannered Mare.
At the end of the episode, he speaks to Ysolda, who shows interest in a relationship with Crotch. They immediately decide to get married after one conversation and a total of two interactions. In a way, the fake character, Sam Guevenne, plays matchmaker to Crotch Guzzler and Ysolda
Trivia
He appears in Daedric Blind Date and Playnord for the same scene.