Joel Murphy is a member of the Celebrity Five, five human criminals that work directly for Loki Laufeyson. In his daily life he is also a famous rock musician. When working for Loki, he always wears a Mayan like mask.
Murphy's first task for the Celebrity Five was to hunt down the kids that had accidently been given biocodes during the incident at the Raft. He and Abomination tracked down Chris Taylor, who at the time was being visited by Spider-Man in his apartment. The two managed to take Spider-Man captive and also steal the DISKs containing Hulk and Wasp. Murphy took both to the Celebrity Five's ship, so that Diablo could mind control Hulk into attacking an Air Force Base. The Avengers managed to thwart this plan however. When they attacked the ship to rescue Edward, Jessica and Spider-Man, Joel Murphy was forced to flee along with Loki and the other Celebrity Five members.
Joel confronted the Avengers and their Partners several more times, like in the battle with the Wrecking Crew. When Loki was initially defeated in the battle at his Ice Palace, the Celebrity Five were arrested. The team was broken out of prison transport by Crossbones, who proceeded to steal their Biocodes and then forcefully drafted them into Hydra. Like his fellow Celebrity Five members, Joel hated being a Hydra soldier. Joel was ordered to help Abomination guard one of the 5 Gaia Anchors with which Red Skull intended to destroy the world. When Edward Grant and Hulk come to the Raft to destroy the Anchor, the Celebrity Five actually helped them accomplish this goal since they wanted to see Red Skull fail. Joel gave Ed a new hero DISK, namely Power Man for this mission. Then, he and Okuma Jubei dressed Ed up as a Hydra soldier and helped him get further into the complex before sending them on his way. When Ed was gone however both gloated that whether Ed would succeed or fail, they would get something they want out of this (either Red Skull being thwarted or Ed dying).
When Red Skull was likewise defeated and Hydra dissolved, Joel and the other Celebrity Five became fugitives. With their reputations destroyed, they visited their old lair to salvage whatever valuables they could find. It was here that Loki contacted the group again from the other dimension he had been banished to. He restored their biocodes and ordered them to prepare for his return, starting with an attack on a security conference. Presumably to steal the passwords for all security systems of the countries represented at the conference, but in reality to steal some energy from Iron Mans' Build Up Armor. While his fellow Celebrity Five members disguised themselves as building staff and tried to sneak into the conference, Joel tried to regain some of his lost fame by making a grand entrance on the stage, playing his guitar. 
After Ronin also joined the Celebrity Five, they were ordered by Loki to steal the Treasures of Darkness for him, which he needed to powerup a machine called the Dark Gate device and open an even greater portal to the Dark Dimension in order to release Dormammu. Backed up by the Wrecking Crew, Joel was responsible for obtaining the final 2 of these treasures. With his team he easily stole the Crescent Dagger, which was hidden in a tower guarded by Hulk and Wasp. For the last treasure, the Solar Crown, Joel and his team travelled to Egypt. Here, the Avengers managed to defeat the Wrecking Crew, but Joel still got the crown after Ronin came to his aid. 
When the Avengers and their partners discovered Loki's true plan and came to destroy the Dark Gate device, Tim and Joel confronted the group with their latest villains, Bi-Beast and Iron Monger. Both villains were defeated, but the Avengers could not prevent Ronin from opening the portal. However, once the portal was opened, it became clear that Dormammu and Loki had no intention of giving Joel and the other Celebrity Five members a role in their conquest of Earth, and Dormammu dragged Joel into the Dark Dimension.
After both Loki and Dormammu are defeated, Joel and the other Celebrity Five members somehow escape the Dark Dimension again, and at the end of the series they are still at large. How they escaped remains unknown, but it is suggested Loki had something to do with it.
Powers and Abilities
Murphy has a green biocode installed in his body, allowing him to d-smash power type villains from their DISKs as well as d-secure them back into their DISKs.