does Bad Things Guy is an evil identical twin brother of Brooklyn T. Guy in the SML series. He was the was the fill-in for Brooklyn between 2016-2017 from "The Hitman" to his main antagonistic appearance in "The Secret Door".

He was a serial killer who killed over 26 people (Including Bowser Junior in the SML Short "Pinch! Pinch! Pinch!" though his death was non-canon).

He made his grand return in "The Secret Door 2" where Craig falls for his trick of not returning to earth and revives him. At the end, Brooklyn Guy and Does Bad Things Guy get into a fistfight, causing them to be mixed up, and marvin has to make the decision on which one to kill. It is heavily hinted that he killed the wrong one, as "Brooklyn Guy" stares into the camera menacingly.

Does Bad Things Guy returns in "The Secret Door 2 ". He tricks Craig the Devil into reviving him. After doing so, DBTG is back at the secret door, he finds out all of his "legacy" was cleaned off, with only Halloween decorations remaining. He goes around the house to find out if people still living there. He then finds Marvin, who is calling Brooklyn Guy to get a toothpick out of Jeffy's eyelid. DBTG sees the opportunity to take down his brother and take his place once again. He does so by locking Brooklyn in his own trunk and knocks him out. He then dresses as a doctor and goes to the front door, pretending to be Brooklyn Guy once more, in which Marvin was already there. Marvin then gets concerned about "Brooklyn Guy's" head, which "Brooklyn Guy" tells him a lie. They then go inside the house into the red couch. After Rose and Marvin couldn't keep their mouths shut about "Brooklyn's" lie. "Brooklyn" tells them that he'll take Jeffy to another room to do surgery.

DBTG tricks Jeffy into going in the secret door and tortures him. Rose then gets concerned about Jeffy, so she and Marvin go look for him. Rose then goes to the secret door and interrupts DBTG's torture section, DBTG lets Rose in and knocks her out. Rose, however, screams before being knocked out, and Marvin, who was asking Braxton if he saw Jeffy, hears it. Marvin asks if he Braxton heard it and he says no. DBTG eventually kidnaps Chef Pee Pee and locks Marvin outside. He then tortures all three of his victims until Simmons, Marvin and a now free Brooklyn Guy go inside the house. The door was a boobytrapped so Simmons gets shot. Brooklyn Guy goes in and fights his evil twin until Marvin points the gun at both, who were both naked and wearing a bandage on their head. Marvin eventually shoots one of them. "Brooklyn Guy" then helps everyone one out while making jokes about killing them all. In the very end, "Brooklyn Guy" stares menacingly at the camera with creepy music.