Pre Karate Kid
According to Tommy he had a crush on Ali Mills (Johhny's ex-girlfriend) and joined the Cobra Kai Dojo in order to develop the courage to ask her out. In the 1983 All-Valley Tournament he lost to Johnny in the finals but put up a tough fight according to Johnny. He also upset Darryl Vidal in the quarterfinals.
The Karate Kid
Tommy is first shown arriving at the beach on his motorcycle along with the rest of his Cobra Kai friends. When Johnny, the leader of the Cobra Kai, gang spots his ex girlfriend Ali Mills talking to Daniel LaRusso, Johnny goes to talk to her while Tommy and the others follow him.
On one night when Daniel was riding his bike home Tommy and his friends approach him with their motorcycles and knock him down the hill
When he along with Johnny's gang were beating up Daniel at the park, Mr. Miyagi jumps in and beats them all up.
After it is confirmed that Daniel will fight in the all valley tournament, his sensei John Kreese instructs the students not to bother Daniel until the tournament. The next day at school Daniel openly taunts and makes fun of Tommy along with his friends because he knows they are not allowed to hurt him.
He faces Daniel in the 4th round in the All Valley tournament. Despite managing to score a point against Daniel, Daniel is able to beat him. Following his defeat he angrily walked away. He vocally expresses his support for Johnny during the semifinals and finals. Johnny however loses to Daniel in the finals.
The Karate Kid Part II
Following Johnny's loss to Daniel Kreese angrily berates Johhny and chokes him in the parking lot. Tommy tries to convince Kreese to calm down and let him go. However, his attempts and pleas eventually cause Kreese to hit him. Fortunately Daniel's teacher Mr. Miyagi saves Johnny by defeating Kreese.
Karate Kid Part III
Despite not making an appearance it can be implied that Kreese's actions following the loss at the All Valley tournament caused Tommy and the rest of the Cobra Kai members to leave the Dojo for good.
Pre Cobra Kai
Sometime between 1984-2018 Tommy was diagnosed with cancer and was hospitalized as a result. It is unknown when exactly this happened, but it can be implied that he was diagnosed prior to the episode "Take a Right".
While Tommy does not make an appearance, he is shown in a few flashbacks, and when Johnny talks to his student Miguel Diaz about Daniel he references he time he fought Miyagi at the park and even says he thinks Tommy suffered brain damage as a result.
During the Summer of 2018, Johnny Lawrence received a phone call from an older Bobby Brown informing him that Tommy wasn't expected to live for much longer. Upon arriving at the hospital, the 2 former Cobras and Jimmy met up with a dying Tommy. After a final day of drinking, fighting a group of guys causing trouble and riding on motorcycles like the four did in high school, they go camping in the mountains where Tommy spends his final moments talking with Johnny. The three Cobras wake up to find that Tommy had died peacefully in his sleep, saddening them.
Tommy was a bully just like the rest of Johnny's gang. He was known for being extremely vocal, as he would scream out of joy or anger from time to time. Despite his mean personality, he did care about Johnny, and even tried to persuade Kreese to stop hurting Johnny following the latters loss at the All Valley Tournament.
34 years later he is much more calm and peaceful. Despite dying in hospital, he spent his final moments happily reconciling with Johnny, Bobby and Jimmy. Like the rest of the old Cobra Kai members, he heavily distrust Kreese.
- Judging by his physical appearance and utilizing hospice care, it is likely that cancer is what took Tommy's life.
- Tommy's fate is ironic and somewhat humorous, as he was literally put in a body bag.