Marlon worked as a cashier at Manny's Truck Stop where he sought out people that he figured wouldn't be missed. For twelve years Marlon fed Terrance Clegg's operation by tipping him off to the people that he noticed in exchange for a fee.
When Wendy Hanscum came through town, Marlon hit on Wendy while she paid which freaked Wendy out due to the creepiness of Marlon's behaviors. Marlon followed Wendy and alerted Clegg to Wendy's presence in town, allowing Clegg and his partner to kidnap Wendy.
After a trucker pointed to Marlon as a possible suspect, he was visited by hunter Dean Winchester and Officer Doug Stover seeking information. Pretending to know nothing more than anyone else using Clegg's website aside from the fact that he turned people over to Clegg, Marlon showed Dean and Doug Clegg's website after Dean got violent.
Marlon was brought along with the hunters and Doug after Clegg pretended to help the Winchesters track down the origin of the website. Armed with a gun, Doug was left to guard Marlon who was handcuffed to a door. Once the Winchesters, Clegg and Donna Hanscum were gone, Marlon revealed his true nature as a vampire to Doug. Breaking free, Marlon attacked Doug, disarmed him and knocked Doug to the ground. Declaring "let's have some fun," Marlon bit open his wrist and spilled his blood into Doug's mouth, transforming Doug into a vampire as well.
By the time Dean and Donna found Doug, he had fully transformed into a vampire and Marlon was gone. As Dean explained the vampire cure to Donna, Marlon returned and announced that they would need his blood to complete the cure. Laughing, Marlon taunted that Clegg had tricked Dean and had Sam. Though Dean demanded to know where Clegg was, Marlon stated that Dean shouldn't have been so rough with him and that he held a grudge. As Dean prepared to attack Marlon with a machete, Donna kneecapped Marlon with a shotgun. Donna ordered Dean to get Marlon's blood and mix the cure while she held her shotgun to Marlon's head and demanded Clegg's location. Though Marlon refused as he knew Donna would kill him, Donna warned "oh I'm killing you either way. You just gotta decide if you want it fast or slow."
Finally, Marlon gave up Clegg's location and Donna killed him. Using Marlon's blood, Dean was successfully able to create a cure for Doug that turned Doug human again. Marlon's information led Donna and Dean to Clegg's location, allowing them to rescue Sam and Wendy.
Powers and Abilities
Marlon possessed the regular powers of a vampire.
- Super Strength - As a vampire, Marlon possessed greater strength than a normal human. Marlon was able to break free of handcuffs with ease and overpower Doug Stover.
- Fangs - Vampires possess a set of retractable fangs. Their teeth are superhumanly strong and can rip open a human's neck and leave huge bite marks on the corpse of the victim it has fed on.
- Super Speed - As a vampire, Marlon's speed was greater than a regular human.
- Super Agility - Vampires possess amazing agility. They can climb up walls and jump off buildings without hurting themselves.
- Super Senses - Vampires have extremely keen senses that are superior to those of humans. They can see in the dark, hear a human's heart beat, and possess an enhanced sense of smell. A vampire can track a human's blood over long distances.
- Immortality - Vampires can potentially live forever. They can't grow old and don't acquire conventional diseases that affect humans.
- Invulnerability - Vampires can not be killed by conventional methods, such as stab wounds or gunshots. However, being kneecapped with a shotgun caused Marlon considerable pain and threats of further bodily harm caused Marlon to give up the location of Clegg.
- Regeneration - As long as they have enough human blood, vampires can heal any wound short of amputation.
- Super Stamina - As a vampire, Marlon possessed great stamina.
Marlon possessed all the weaknesses of a vampire.
- Serious Physical Injury - By kneecapping Marlon, Donna was able to cause him excruciating pain and effectively disable Marlon. Threats of further serious physical harm caused Marlon to cooperate.
- Decapitation - Like all vampires, Marlon could be killed through decapitation.
- While Marlon's death is not shown on-screen, Donna Hanscum stated unequivocally that she intended to kill him. She may have also used a shotgun to blow his head off rather than cutting it off with a machete as she threatened Marlon with a shotgun to the head at point-blank range.
- Marlon appeared to be aware of the vampire cure and what it entailed or at least that it needed his blood.
- Marlon is the only vampire that had their blood extracted for the vampire cure while they were still alive.
- Dean tells Marlon "bring it Twilight," a reference to the Twilight series of vampire novels and movies. Dean also said something similar to a vampire he killed in Free To Be You and Me.
- Marlon can be considered a revenge seeker as he refused to help Dean due to the grudge he held for Dean's earlier rough treatment of him.