Luna, more commonly known as the Moon, is Earth's only natural satellite, it is, among the satellites of major planets, the largest relative to the size of the object it orbits. It appears in a few episodes, beginning with "Home Sweet Pineapple." It is a major plot point of the episodes "Sandy's Rocket" and "Mooncation."
The moon usually appears within the show as a typical animated moon. However, in episodes such as "Sandy's Rocket" and "Mooncation," the real-life celestial body is shown.
Sandy first mentions the moon after SpongeBob asks what she is going to do with her rocket. She then says that she is going to the moon and shows it on a poster. SpongeBob then asks if he can go with her, but Sandy tells him "no." However, after some persuasion, Sandy allows him to go. He then runs around the rocket mentioning that he is going to the moon.
Later, Sandy has a Pop-Gun and SpongeBob asks if they are going to hunt on the moon. Sandy says that it is for harvesting moon rocks. Soon, Sandy says that she has been to the moon and there are no aliens there.
Later, after starting the rocket, Patrick and SpongeBob find themselves in space. Unknowingly, they orbit the moon for a while and then fall back to Bikini Bottom. Sandy follows the rocket using a jet pack and finds the two are not there.
Meanwhile, in Bikini Bottom, SpongeBob and Patrick think they have landed on the moon. After capturing Gary and Squidward with the net guns, thinking that they are aliens who are projected to look like Gary and Squidward, SpongeBob and Patrick find Mr. Krabs and Mr. Doodles outside Squidward's house. The two hold him up and Mr. Krabs tells them to shoot him, but not his money. SpongeBob then says that they do not want his money and calls him a "moon man."
After capturing everyone in town, the two face Sandy and capture her as well. She tries to tell the two that they are not on the moon and in Bikini Bottom, but the two close the rocket's hatch before she can finish.
After Patrick accidentally captures himself, SpongeBob goes back to the moon thinking that he is going to Bikini Bottom. When he gets there, he realizes his mistake.
It appears at Floater's Cemetery, next to the sign. It also appears behind a ship in the cemetery. It later appears when Mr. Krabs does his jump above the skeletons. It then appears with Bikini Atoll, while Mr. Krabs' fighting noises can be heard.
It first appears in the episode, when SpongeBob and Patrick think that the Fisherman was after them. It is revealed to just be Jellyfish clumped together to make a silhouette similar to that of the Fisherman.
It later appears twice when Squidward dresses up as the Fisherman.