Jimmy Manson, also known as "Wee Jimmy Manson", was a 3ft tall hippy musican who once auditioned for the role of guitar player for the Gorillaz at Kong Studios, but was turned down along with others by Murdoc after the job was taken by Noodle. He seems to be based on Charles Manson, both have similar hair and are criminals/villains.
At one point, Jimmy auditioned to be a guitarist for Gorillaz, but got rejected by Murdoc and the others.
Gorillaz Phase 2: 2004-2007
Years later, Jimmy became the head of the Gorillaz music label Stateside. When he toured with Gorillaz during the Deman Detour, the Mexican inmates who helped Murdoc escape jail (and perform the music for "White Light") recognized him.
Back in 1999, Jimmy was imprisoned in Tijuana, Mexico for vagrancy/petty car crime and shared the same cell as the Mexican inmates who Murdoc became friends with. While in prison, Jimmy spends the time plotting his revenge against many artists who had rejected him in the past and openly talking about it with the Mexican prisoners. Now he had a plan to kill off Gorillaz and cash in on their success.
During the production of the "El Mañana" video in 2006, Murdoc approached Jimmy and offered to team up with him to complete his plan. Murdoc was to secretly stash a couple of guns in the windmill tower on the floating island and Jimmy was to hide inside the tower and wait until the helicopters start firing. Then Manson was to come out from hiding, get the guns, kill Noodle and parachute off the island. The cameras started rolling on March 7th, 2006. As the helicopters fired on the windmill island, Jimmy discovered that Murdoc had set him up by locking him in the tower with no guns. While Noodle parachuted off the island safely, the island crashed, burned and was blown up and killing Jimmy Manson in the process. Murdoc was the last to see him alive.
In the Gorillaz autobiography, Rise of the Ogre, Murdoc stated:
"There's no way on earth I'm killing Noodle. Are you mad? She's Noodle. We're Gorillaz! The greatest band on earth. I'm arrogant, ruthless even, but I'm not stupid. I'm not having some two-bit mouldy despot record company nut killing off my band. No way, Jose. That clown got what he deserved... He set himself up and burned all the evidence in the process. Instant Karma for Mr. Jimmy Manson."
When asked if he felt any remorse? He also stated:
"Not a jot, it was him or us. And it's not gonna be us now, isn't it. So there you go. 'Jimmy Manson'. He wasn't big and he wasn't clever."