On "Best Friend's Day," Patrick gives SpongeBob an enormous wad of used gum he has amassed over his entire lifetime (fondly referred to as "Gummy"), and SpongeBob finds it a better gift than his own (a robotic butler). However, when he takes it inside, he realizes how disgusting it is, and it even starts to scare him, with a pair of underpants crawling out of the gum and saying in a demonic voice, "You're not Patrick!" First, SpongeBob tries to throw it away, but Patrick catches him in doing so, and he says that he was dressing it up with the garbage can. Later, SpongeBob tries to bury Gummy, but Patrick catches him again, and he says that he dug the hole to be able to look at Gummy from below. Patrick insists that it must be displayed properly, and places it above SpongeBob's doorway. SpongeBob next tries to dispose of it in the night, and in the process frees several people who were literally trapped inside it. He tries to pull Gummy off of his house, and fails, destroying the ball and getting stuck to it in the process.
The next day, Sandy visits SpongeBob's house to see it covered in the sticky remains of Gummy, with SpongeBob hanging above his doorway. She tries to free him by lassoing a piece of Gummy onto a passing truck, which is almost able to pull it away, but is ultimately pulled in by it, hitting SpongeBob's house and causing the gum to explode, completely covering the houses of SpongeBob, Squidward and Patrick, and trapping Squidward and Sandy as well. Patrick then appears, and SpongeBob tells him he can have Gummy back. Patrick then wolfs down all of the gum making Patrick obese, freeing SpongeBob, his friends and their houses. However, he then hiccups a massive bubble, which explodes and covers the whole town in gum.
The name of this episode is a reference to "The Gift of the Magi."
At the end, during the cleaning of the gum, Patrick ate some of the gum like Pac-Man.
Robo 2.1 is similar to C-3PO from Star Wars as he has a similar voice and said a similar phrase to C-3PO's when introduced in the episode.
SpongeBob drives a bulldozer in this episode, but he doesn't have a driver's license and still doesn't know how to drive.
When SpongeBob "steals" Gummy and gets trapped, he is wearing a burglar outfit. However, when Sandy sees him trapped, he's wearing his normal clothes.
After Sandy gets her hand stuck in the gum, she takes her hand back out when she saw the truck passing by, as if her hand was never stuck in the first place.
The truck driver calls his truck, "Old Blue" even though it's red.
Before SpongeBob "steals" Gummy, he looks over to Patrick's rock, but Squidward's house is nowhere in sight.
After Gummy explodes onto SpongeBob's house, all of the nasty trash stuck to it disappears.
When SpongeBob shows his present to Patrick, Patrick's mouth disappears.
Towards the end of the episode, SpongeBob says that it's still Best Friends Day. This is inaccurate because a night had passed.
When SpongeBob puts Gummy away in the rubbish bin, the dirty pizza and other dirty things disappear.
When everything gets covered in gum, the flower on Sandy's helmet swapped sides.
During the opening shot (including near the ending), the windows of SpongeBob's house and the chimneys are on the wrong side of his house.
Patrick destroyed his rock to get Gummy out to SpongeBob. The next time there is an outside scene, his rock is back the way it was.
When Patrick was getting ready to go home in the beginning, Gummy is a lot smaller than usual.
Before SpongeBob gives Gummy back to Patrick, he tells him that it's still Best Friends Day. However, the episode took place over two days. This error is further reinforced by SpongeBob saying "Well, it's still Best Friend's Day..." close to the end of the episode. As a result, SpongeBob could have been trying to trick Patrick into taking Gummy back, or Best Friends Day is a multi-day holiday.
When SpongeBob was raiding his closet, a baseball lands on the floor near Gary and then disappears.