Tha Free World are a group of battle rappers. They are the supporting antagonists of the movie, and they haze B-Rabbit's Crew (The 313) in the movie often, both by battle rapping and physical violence. One member even threatened B-Rabbit with it.
Tha Free World gang appear shortly for the first time at the beginning of the movie during the cypher at the Shelter when Future's boy "Shorty Mike" is battling Papa Doc. They can be also seen later laughing and making fun of B-Rabbit after he fails to battle against rapper Lil' Tic. Then they appear at the parking lot, heckling the rappers there. When Lyckety-Splyt makes fun of B-Rabbit for choking the last night, B-Rabbit attacks him and the fight ensues. It ends up in a draw, when Wink makes both teams stop fighting, as he is friends with both crews. They are later seen outside a street, when B-Rabbit punches Lyckety-Splyt, and a fight ensues, which is stopped when Cheddar Bob shoots himself in the leg accidentally. Later, Alex, B-Rabbit's lover, cheats on him for Wink, and B-Rabbit beats him up. Because of this, Wink leaves B-Rabbits crew and gives his full loyalty to The Leaders of the Free World, who go on to get revenge by jumping a lone B-Rabbit.
Later, two members of the crew rap battle B-Rabbit at the shelter, but B-Rabbit manages to trounce them all, causing The Leaders of the Free World to leave the shelter, and the audience cheering "313 F**k free world"!