Unkar Plutt is a fictional male in the Star Wars series. The character was portrayed on screen by Simon Pegg. His allegiance is to no one in the series. Unkar Plutt is a scavenge trader on Jakku. Rey visits Unkar with items that she's scavenged from a crashed Star Destroyer. Unkar is only in it for himself, he sees the BB8 droid and offer lots of rations for the droid but Rey decides to not trade him in. When Unkar Plutt can't get his own way, he sends in the heavies to get the droid but he is defeated by Rey.
One of the items that Unkar Plutt has in his possession is the Millenium Falcon, the ship that Han Solo calls home. Somehow Han Solo lost the ship and it ended up on Jakku which is when Rey steals the ship.
Unkar Plutt is played by British actor Simon Pegg who is more famous for playing Lt. Cmdr. Montgomery Scotty Scott in the rebooted star Trek films. Simon Pegg has been avid Star Wars fan for years and has tried to reference them in his past films and television series (Spaced)