Zukka

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

Canon
Sokka and Zuko started off as enemies because Sokka was friends with Avatar Aang whom Zuko was trying to capture. They never really had any social interaction until Zuko decided to switch sides and join Team Avatar at the Western Air Temple. Sokka was strongly again allowing Zuko to join the team and most agreed with him. However, Aang changed is mind so Sokka supported him. He was nervous while showing Zuko to his room but Zuko simply smiled at him.

Sokka made fun of Zuko and Aang while they were practicing their firebending. When Zuko claimed that he no longer had the rage that powered his firebending, Sokka joked that everybody should try to make him mad. Sokka was eventually so upset that his father was captured so he and Zuko went to the Boiling Rock to rescue him. Hakoda was not there at first but when more prisoners arrived Zuko convinced Sokka not to give up and they escaped along with Hakoda and Suki.

Sokka and Zuko got along much better after the escape from the Boiling Rock. He even led a toast for Zuko's bravery in protecting Team Avatar from Azula. Zuko was upset about Katara still not trusting him so he went over to Sokka's tent. Sokka was posing with a rose and was embarrassed to see Sokka there instead of Suki. Zuko begged him to explain what happened to Kya so Sokka told Zuko everything that he knew. They remained friends and allies following the end of the war.

Fanon
Zukka is a popular ship in the Avatar fandom and one of the most popular slash ships. Many ship them together because of their "life-changing field trip" that they took to the Boiling Rock. The fact that Zuko refused to let Sokka go without him showed that Zuko really cared for him. A lot fans also joked about the moment when Zuko went into Sokka's tent and found him posing with a rose.