Johnny Lawrence

Johnny Lawrence is a fictional character who was played by Billy Zabka in the 1984 movie The Karate Kid and its sequel The Karate Kid Part II and is one of the two protagonists of the television series Cobra Kai.
Role in The Karate Kid.
Johnny Lawrence has a girlfriend named Alli Mills but she breaks up with him. Johnny sees her talking to a kid from New Jersey named Daniel LaRusso at a beach so he pushes Daniel to the ground and tells Alli to talk to him, takes her radio from her and says that he won’t give it back unless she talks to him. When she doesn’t, he smashes her radio and starts yelling at her. When Daniel tells him to stop, Johnny throws the radio at him so Daniel attacks Johnny with the karate he knows from the YMCA. But it turns out, Johnny has a black belt in karate given to him by a sensei named John Kreese at a dojo called Cobra Kai. So Johnny beats Daniel in a fight, beats Daniel up, punches him in the face and kicks him in the chest and groin. Then Johnny’s friends all join him in bullying Daniel. Because of that, Johnny gets the nickname The Karate King. Johnny and his friends later bully Daniel at Alli’s soccer try-outs and get Alli banned from soccer. Johnny goes to take a karate lesson at his dojo Cobra Kai where Sensei John Kreese teaches him that “the enemy deserves no mercy” and finds out that Daniel was thinking about taking lessons there, so Johnny and his friends crash their motorcycles into Daniel’s bicycle, while he’s riding it, attack him with their martial arts and push him off a hill. At a Halloween party, Johnny goes to the bathroom and Daniel sprays him with water for revenge so Johnny and his friends chase Daniel outside and beat him until he’s almost unconscious. Then Johnny’s friend Bobby thinks that Daniel is in serious danger and tells the others that they should stop but Johnny tells him that they will never stop because “the enemy deserves no mercy”. Then Mister Miyagi sees what’s happening so he attacks Johnny and his friends with his karate and rescues Daniel. When Johnny sees Mr. Miyagi and Daniel at his dojo he tells his Sensei John Kreese what happened and Kreese tells Miyagi to tell Daniel to fight Johnny so Miyagi says that they can fight at the karate tournament but until then Kreese has to tell Johnny and the others to stop bullying Daniel. Kreese agrees but says that if Daniel doesn’t fight then he’ll tell Johnny and the other that it’s “open season on this boy. Johnny later pretends to be nice when adults are around so that people won’t believe that he’s a bully. Johnny later tells Alli to break up with Daniel and be his girlfriend again. Alli says no but Johnny kisses her anyway so she slaps him. At the tournament, Johnny makes fun of Daniel for not knowing how to put on a karate uniform and in the last round Johnny’s Sensei John Kreese tells him to “sweep the leg” to beat Daniel and Johnny doesn’t want to do that but then does it anyway because Kreese told him to do it. Daniel then beats Johnny. Then Johnny hands the trophy to Daniel and tells him “Here. You deserve it. You know, LaRusso, you’re all right”.
Role in The Karate Kid Part II.
In the prologue of the movie, The Karate Kid Part II, Sensei John Kreese of Cobra Kai yells at Johnny Lawrence and tells him he’s a loser for having only gotten second place, destroys Johnny’s second place trophy, puts him in a headlock, pushes him to a car and starts choking him but then Mister Miyagi sees and fights Kreese to save Johnny.
Character based on him in the remake.
In the 2010 movie reboot of The Karate Kid, Dre’s bully Cheng is based on Johnny Lawrence but uses kung fu instead of karate. 
Role in Cobra Kai.
In Cobra Kai, an adult Johnny Lawrence is asked by a kid named Miguel Diaz to teach him his karate so that Miguel can defend himself from his bullies but Johnny says no. But after meeting the adult Daniel LaRusso, who got rich selling cars, Johnny realizes how much he hates Daniel and starts his own dojo that he calls Cobra Kai to teach Miguel. Johnny teaches his student “strike first, strike hard, no mercy” but after seeing his students Miguel and Hawk hurt Johnny’s son Robby in the tournament Johnny tries to change Cobra Kai karate to give it honour but then John Kreese comes back, takes over the dojo and forces Johnny out for weakness so Johnny takes Miguel out of Cobra Kai and starts his own dojo called Eagle Fang which ends up working with Daniel LaRusso against the Cobra Kai dojo. Johnny also falls in love with Miguel’s mother Carmen and gets her pregnant.