Richard Throckett Straker was the secondary antagonist in Stephen King's novel, Salem's Lot.
History
In the original novel, Straker was Kurt Barlow's 'familiar' or human thrall. All of Barlow's business concerns were enacted by him. Straker bought the Marsten House and prepareed the way for his master. He was presented as a Satanist and showed his devotion by killing Will Purinton's dog as a sacrifice. After Mark Petrie wounded Straker during his escape from the Marsten House, Straker was drained of his blood by Barlow who was unable to resist feeding on his servant. Barlow was furious at that turn of events, as he considered Straker the best servant that he ever possessed.

James Mason as Straker in the 1979 Minseries.

Donald Sutherland as Straker in 2004 Miniseries.
In 'Salem's Lot (2004), Straker's name was once again changed, that time into Richard Thomas Straker. Although Straker had more screen time than Barlow in that version also, his role was somewhat reduced from that of the original mini-series. He was also never actually seen in any of the same scenes with Barlow. In that version, Straker was killed as in the novel: he was left hanging upside down from the rafters of the Marsten House and was drained of his blood. However, it was unclear if Straker was killed by Barlow, since it was established in the 2004 mini-series that the Marsten House itself had some kind of evil entity that dwelled inside it that had previously killed Hubie Marsten in a similar way.