Sensei John Kreese is a Vietnam War veteran and the sensei of the Cobra Kai dojo. He instructs his students to have no mercy towards their opponents. In the first film, Kreese's best student, Johnny Lawrence, has a conflict with Daniel LaRusso. In response, Mr. Miyagi teaches Daniel karate. When Daniel and Miyagi resolve the conflict at the Cobra Kai dojo, Miyagi proposes that Daniel should enter the All Valley Under-18 Karate Championships tournament, where he will face the Cobra Kai students and demands that the conflict will cease while Daniel trains. Kreese agrees to the idea, but threatens to allow his students to continue their harassment if neither show up at the tournament. At the tournament, Daniel reaches the semi-finals while Johnny advances to the finals after defeating a highly skilled opponent. Kreese instructs Bobby Brown, one of his more compassionate students and the least vicious of Daniel's tormentors, to disable Daniel with an illegal attack on the knee. Bobby reluctantly does so, getting disqualified in the process. However, Daniel recovers and ultimately defeats Johnny, becoming the new champion.
The Karate Kid Part II
Shortly after Daniel's victory in the tournament, Kreese attacks Johnny for losing the tournament, but is approached by Miyagi, who humiliates Kreese by making him punch car windows, leaving the latter with bloody fists. Miyagi subdues Kreese and the Cobra Kai students eventually abandon him.
The Karate Kid Part III
Six months after the tournament, Kreese is now broke and destitute as he returns to the Cobra Kai dojo, which has been closed since Kreese lost all of his students. Desperate to resurrect his career, Kreese visits his Vietnam War comrade, Terry Silver, who has become a wealthy owner of a toxic waste disposal business and offers to help Kreese gain revenge on Daniel and Miyagi and re-establish Cobra Kai. Silver sends Kreese to Tahiti on vacation to regain while he hires Mike Barnes, the current under-18 national karate tournament champion, to harass Daniel and beat him in the next upcoming tournament. As Silver unknowingly trains Daniel, both of them are at the dojo one night, where Kreese make his way back in the fray with Barnes by his side to attack Daniel. Miyagi intervenes and escorts Daniel out of the dojo before any further chaos can occur. During the tournament, Daniel defeats Barnes, prompting Kreese and Silver to leave the scene, implying that Cobra Kai is finished for good and due to Barnes, Kreese, and Silver's behavior getting the dojo banned from sports.
Cobra Kai
Kreese returns in the first-season finale of Cobra Kai and faces his former pupil Johnny Lawrence, who reopened Cobra Kai and went on to win the recent All-Valley Karate Championship. In Season 2, Kreese asks Johnny for forgiveness for attempting to kill him after losing to Daniel back in 1984. He also explains that after the original dojo closed down, he spent his life running strikes during the Gulf War and training soldiers in the War in Afghanistan. The animosity between the two cools down when Johnny allows Kreese to attend Cobra Kai classes as an observer. Johnny and Kreese encounter Daniel, who realizes that Kreese has faked his death once again. Kreese tries to provoke Daniel by saying that “the gang’s all back together...almost all of us”, referring to Mr. Miyagi's death. He offers insincere condolences, smiling at Daniel, but the smirk is erased from Kreese's face when Daniel counters by asking him “how are the knuckles”, referring to the time he was defeated by Mr. Miyagi after Daniel won his first tournament. Later, when the Cobra Kai's students become concerned about Kreese's attitude and his war stories that do not add up, Johnny follows his former sensei to a homeless shelter. Kreese admits that he failed a psychological test when he attempted to re-enlist in the army and his war stories were lies. Feeling bad for Kreese, Johnny decides to put his full trust in Kreese, believing that he wants to change for the better. However, Kreese quickly becomes a negative influence on Johnny's students, going so far as to encourage some of them to vandalize the Miyagi-do dojo. After seeing the tactics used by his students during a war game at Coyote Creek, Johnny discovers that Kreese has been teaching the old ways of Cobra Kai behind his back and kicks him out of the dojo. After Miguel is severely injured in his fight with Robby at school, the students lose faith in Johnny and side with Kreese, who reveals to Johnny that he convinced strip mall landlord Armand Zakarian to take the dojo away from him. Now being its sole sensei, Kreese hopes to turn Cobra Kai back to the ruthless organization it once was.
Conception
The character of John Kreese was originally written for Chuck Norris, but he turned down the role because he thought it would give karate a negative image. The character was based on Robert Mark Kamen's friend Ed McGrath. Martin Kove got the role by being verbally abusive towards the director.
Reception
The character has had a mostly positive reception from critics and is viewed as a quintessential 1980s villain.