Jayvon Simson is a character in Grand Theft Auto IV. He was a member of the North Holland Hustlers. He was a small time drug dealer and was therefore wanted by the police. To avoid being arrested by the LCPD, he became a police informant and ratted out his fellow gang members including leader Dwayne Forge. When Dwayne was incarcerated, Jayvon started to date Dwayne's girlfriend, Cherise Glover.
When Dwayne got out of prison, he went to his former apprentice Playboy X, who connected him with Niko Bellic. Dwayne sent Niko to kill Jayvon, who was, at the time, with Cherise at an arcade in Chinatown. Jayvon managed to get on his bike and fled, while being followed by Niko, who eventually killed him and took his money back to Dwayne.
Should the player chase Jayvon long enough, he will eventually crash his motorcycle; however, instead of fleeing from Niko like other NPCs in the game, he will simply stand there, with an angry look on his face. He will not do anything, even if Niko points his gun at him at close range. He may, however, eventually take out a sub machine gun and start shooting.
Jayvon may look entirely different each time the player does the mission. He may, for example wear a green camouflage sweater, brown cargo pants and black boots, or he may wear a white tank top, black jeans and blue sneakers. This is due to the fact that he uses a random Jamaican Posse character model.