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.
In Salem's Lot (1979), Straker was the main antagonist and a more prominent villain than Barlow, unlike the novel, and was alive until the climax of the mini-series. Though seemingly human, that version of Straker turned out to be someone more with incredible strength, and it was implied that he possessed some kind of supernatural power: Straker summoned a fast wind as he abducted Ralphie Glick in the woods and easily managed to lift Dr. Bill Norton off the ground by himself with little effort and impaled him on a wall that was filled with animal horns. Straker was, however, still mortal and was shot and killed by Ben Mears on the stairs in the Marsten House, though he took several bullets to the abdomen and continued to move until he finally succumbed to his wounds. Straker was English in that version and came from London. His name, according to Constable Gillespie, was actually Richard K. Straker, although it remained unknown what the middle initial stood for.
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.