Joker, a clone trooper sergeant, was stationed in the Jedi Temple Hangar throughout the Clone Wars. He was well-known for sharing jokes to alleviate boredom while on duty. His comrade, Spanner, frequently struggled to grasp the humor of his friend's jokes. Both Joker and Spanner were stationed at the Iceberg Three Republic outpost during a mission to Iceberg Three.
Sergeant Joker made his debut as a Non-Player Character (NPC) within Sony Online Entertainment's online game known as Star Wars: Clone Wars Adventures. He and Corporal Spanner are located within the temple hangar, positioned near the main hall's entrance. Interacting with Joker triggers him to share a joke with Spanner. Distinct from the majority of other NPCs featured in the game, his name remains hidden above his head; however, when he engages in joke-telling with Spanner, the dialog, along with the NPCs' names, becomes visible within the players' chat interface.
The joke mentioned earlier, just one of the many Joker told while in the Jedi Temple Hangar, was originally delivered by Jacen Solo in Star Wars canon.