Happy Nickmas! (Nickelodeon Christmas special)

Main characters

 * SpongeBob SquarePants: SpongeBob, Patrick, Squidward, Sandy, Gary, Mr. Krabs, Pearl, Plankton, Larry, Mrs. Puff, and Patchy the Pirate
 * The Rugrats: Tommy, Chuckie, Phil and Lil, Susie, Kimi, Angelica, Spike, Stu and Didi Pickles, Grandpa Lou Pickles, Betty De Ville, Chas and Kira Watanabe Finster, Charlotte and Drew Pickles
 * The Fairly OddParents: Timmy Turner, Cosmo and Wanda, Trixie Tang, and Tootie
 * Danny Phantom: Danny Fenton/Phantom, Sam Manson, and Tucker Foley
 * Jimmy Neutron Boy Genius: Jimmy, Goddard, Carl Wheezer, Sheen Estevez, Cindy Vortex, and Libby Folfax
 * The Loud House: Lincoln, Lori, Leni, Luna, Luan, Lynn, Lucy, Lana, Lola, Lisa, Lily and Clyde
 * The Casagrandes: Bobby, Ronnie Anne and Sid Chang
 * The Ren and Stimpy Show: Ren and Stimpy
 * CatDog: CatDog
 * Hey Arnold!: Arnold, Helga, Gerald and Phoebe
 * Rocko’s Modern Life:Rocko, Heffer and Filburt
 * T.U.F.F. Puppy:
 * Blue's Clues series: Blue, Josh, Steve, Joe, Tickety Tock, Slippery Soap, Mr. Salt, Mrs. Pepper, Paprika, Cinnamon, Sage and Ginger, Shovel and Pail, Sidetable Drawer, Mailbox, Magenta, Miranda, Marlee, and Periwinkle
 * Dora the Explorer: Dora, Map, Backpack, Boots, Benny, Tico, Isa, Senor Toucan, Diego, Daisy, Alicia, and Baby Jaguar
 * Little Bill: Little Bill, Elephant, Big Bill, Brenda, Bobby, April, Alice the Great, Andrew, Kiku, Fuschia, and Jamal
 * PAW Patrol: Ryder, Marshall, Chase, Rubble, Rocky, Zuma and Skye
 * Bubble Guppies: Molly, Gil, Eena, Gobby, Oona, Nonny and Bubble Puppy

Background characters

 * Blue's Clues series: Purple Kangaroo, Orange Kitten, Green Puppy, Miss Marigold

Songs

 * Deck the Halls
 * Feliz Navidad - Dora and her friends
 * Decorate the Tree (originally from The Wiggles) - Steve and Patchy ft. Tickety and Blue
 * Jingle Bells (from Carols in the Domain)
 * Twelve Days of Nickmas (newer version)
 * The Night Before Christmas - told by Josh
 * Here Come the Reindeer (originally from The Wiggles) - Steve and Joe
 * Go Santa Go (originally from The Wiggles) - Steve. Joe, and Josh, ft. the rest of the Nickelodeon cast
 * We Wish You a Happy Nickmas

Cast

 * Tom Kenny as SpongeBob, Gary, and Patchy the Pirate
 * Ariana Grande as Tickety Tock
 * Jeff Bennett as Mr. Salt
 * Olivia Holt as Sidetable Drawer