A supposed creature that is mentioned by Squidward in the episode "Hello Bikini Bottom!" After a kid pinned Squidward, Squidward yelled at the kid saying "I am not a Donkey Fish!"
Mario was mentioned by Patrick in the episode "The Bully." Mario apparently works at Pizza Castle. He was mentioned by SpongeBob again in "Suction Cup Symphony" when he thought Squidward "ate at Mario's," the night before.
A character that is the supposed mother of Pearl Krabs. Mr. Krabs commonly mentions this name whenever something surprises him.
A location mentioned by Girly TeenGirl in the episode "The Slumber Party." Girly TeenGirl says she moved from there to attend Pearl's slumber party. However, Pearl didn't believe her (thinking it was SpongeBob in disguise) and she and her friends drove Girly TeenGirl away. As Girly TeenGirl (who is revealed to not be SpongeBob in disguise) is running away, she says while crying "I am so moving back to Farawayville!"
A location that was mentioned by the narrator in the episode "Mermaid Man and Barnacle Boy III." Mermaid Man and Barnacle Boy went on a vacation to this place while SpongeBob and Patrick watched over their lair.
A hospital for domestic pets, mentioned in "Band Geeks," where Squidward's clarinet playing was mistakened for a dying animal. The Purple Doctorfish works there, along with other paramedics.
A restaurant mentioned by Patrick in "The Bully." Pizza Castle may be a parody of Pizza Hut and is a restaurant that serves pizzas. Mario is a known employee that works there.
A location mentioned by Squidward in the episode "Idiot Box." Squidward wanted to arm wrestle with robots on the moon and thought that SpongeBob and Patrick could take him there. However, Squidward is angered not to do so and, a little later, Squidward heard noises of Robot-Pirate Island from the box.
A location and boat mentioned by Mr. Krabs in the episode "Squilliam Returns." Mr. Krabs was the head chef of this ship.
A location and boat mentioned by Mr. Krabs in the episode "Squilliam Returns." Mr. Krabs was a janitor on this ship.
Sizzling Spring Sauna
A location mentioned by Patrick in the episode "Life of Crime." Mr. Krabs went to the sauna and stole a towel from there falsely telling SpongeBob and Patrick that he "borrowed" it.
A town/city mentioned by Patrick in the episode "I Was a Teenage Gary." This is where the Annual Jellyfishers Convention was held.
Food and drinks
A type of food sold at the Chum Bucket that was first mentioned by Plankton in the episode "F.U.N." after SpongeBob knocked on the door. Plankton said "Our special today is Chum... Balaya." It is marked with a "new" sign on the menu. It is never seen in the show. The name is a parody of the Creole dish, Jambalaya.
Diet Dr. Kelp
A drink mentioned by Tom in the episode "Pizza Delivery." Tom was angry that SpongeBob didn't bring him his drink.
Fried Oyster Skins
A type of food mentioned by SpongeBob and Patrick in the episode "Squidville." After Patrick tries to order food through the intercom, SpongeBob mentions that Patrick just ate three orders of fried oyster skins. Patrick then says that he loves fried oyster skins.