Patty

Patty is a Krabby Patty made by in the episode "To Love a Patty." It is a "female" Krabby Patty that SpongeBob falls in love with.

Description
Patty is a meat patty with tomato eyes, lettuce hair, cheese clothes, and ketchup dimples and hair. Its nose is made of a pickle and its mouth is a squirt of mustard.

As the episode goes on, Patty becomes more deteriorated. Green stench comes out of it and Patty is looked to be squashed and off-color. When SpongeBob is singing to it, it falls in the water, which makes it fall apart and start to smell bad. It becomes even more rotten by that night at the Krusty Krab.

Role in episode
SpongeBob made a perfect Krabby Patty that he had named Patty. She would have originally been a tough fish's lunch, but SpongeBob did not want her to get eaten. SpongeBob gives the fish a grilled shoe burger instead and takes Patty to his home.

Patty then has a makeover and hair-cleaning and goes on an adventure with SpongeBob while the latter sings the song "I Can't Keep My Eyes Off of You" to as they get attacked by hungry scallops and fall into the end of a waterfall.

Unbeknownst to SpongeBob, Patty soon becomes disgusting, rotten, and is so terrible smelling that people run away from it. Then, SpongeBob realizes that he must eat Patty, which he does, and due to the repulsive condition of the burger towards its final days, asks for a doggie bag.

Relationship with SpongeBob
While SpongeBob is in love with it, it does not really have any feelings for SpongeBob since it is a sandwich and is thus insentient. SpongeBob is very much in love with it until he realizes that Patty rotted while he was at the Krusty Krab.

After Mr. Krabs tells him about the true purpose of Krabby Patties, SpongeBob then eats it despite its spoiled condition.

Relationship with everyone else
While SpongeBob falls in love with Patty, everyone else knows that it is just a Krabby Patty and are, therefore, not fond of SpongeBob's love with it.

Trivia

 * Patty is seen on the DVD cover of To Love a Patty, dancing with SpongeBob, even though he is holding it.
 * Its rotten appearance is similar to the rotten Krabby Patty in "The Algae's Always Greener" and the Nasty Patty from "Nasty Patty."
 * Patty went through an arguably similar ordeal to the Nasty Patty, as both patties had additional ingredients added to them, and both patties were dropped into dirty water, which contributed to their disgusting state.
 * The two close-ups of Patty being rotten were drawn by Kenny Pittenger, who said on his blog that he wasn't satisfied while working on them.
 * Patty is the only "character" SpongeBob has fallen in love with. It should be worth noting that Stephen Hillenburg confirmed that SpongeBob is asexual, however, this is not synonymous with having no romantic feelings.