Jetko

Jetko is a Slash ship between Jet and Zuko in the Avatar: The Last Airbender series.

Canon
Zuko and Jet first met while they were on a boat to Ba Sing Se. Zuko was complaining about the poor quality of the food that they were served so Jet approached him and told him that the captain of the ship was eating better food. He then offered Zuko to join him and the Freedom Fighters on a mission to steal the food and he agreed. The two succeeded in stealing the food and later talked about their goals in Ba Sing Se. Jet aproached Zuko alone on the ship the next morning and sympathized with him that they were outcasts and should stick together. Jet was very excited about Zuko's skills and tried to recruit him in the Freedom Fighters but Zuko refused.

Jet did not want to give up on recruiting Zuko until he caught his Uncle Iroh heating tea with firebending. Jet then realized that Iroh and Zuko were secretly from the Fire Nation. He immediately informed the other Freedom Fighters of this but they advised Jet to just back down. Jet made multiple attempts to spy on Zuko and Iroh and reveal their true identities. He eventually got impatient and attacked Zuko on the street in an attempt to get him to firebend in front of everybody. However, the Dai Li later broke up the fight and arrested Jet for bringing up the war within the walls of Ba Sing Se.

Fanon
Jetko is a popular ship among the Avatar fans and is one of the most popular slash ships. Many fans feel that they look cute together and have similar "bad boy" personalities. Both were also seen as possible love interests for Katara at one point. What most fans point to is the time that Jet and Zuko spent bonding on the boat. Many were also happy when Jet wanted to recruit Zuko and disappointed when he learned the truth about him and turned on him.