Happy Splatoween is an American 40-minute animated Halloween-themed television special produced by DreamWorks Animation Television for NBC. The story is set in Splatoween, the Inkling species' Halloween celebration. Squidwin and the gang are venturing inside an abandoned pirate ship where is homed to the group phantoms of Pirate Phantoms, and must save Ruthie (which Squidwin is looking after her) from the phantoms.
- Zac Efron as Squidwin
- Liliana Mumy as Pen
- Raven-Symoné as Riri
- Jeremy Shada as Peter
- Olivia Olson as Lima
- Josh Gad as Turner Jackson (or T.J.)
- George Lopez as Judd
- Patric Zimmerman as Li'l Judd
- John Cleese as Cap'n Cuttlefish
- Martin Short as Sheldon
- John Leguizamo as Crusty Sean
- Craig Robinson as Jelonzo
- Anne Hathaway as Annie
- Tom Kenny as Moe, some of the Inkling boys, and additional voices.
- Sandy Fox as Callie and some of the inkling girls
- Deedee Magno as Marie
- Wayne Knight as Earl
- Jack Riley as Mr. Lob
- Wallace Shawn as The Mayor of Inkopolis
- Charles Martinet as a Mario-alike plumper inkling, and additional voices
- Ellie Kemper as Aqua
- Sofia Mali as Ruthie
- Kath Soucie as Lilac "Lil" Teuthida, some of Inkling girls, and additional voices.
- Mark Hamill as Dug, and Mail Stork
- Jess Harnell as Gus
- Jennifer Tilly as Ms. Hummer
- Dan Castellaneta as Jelly, and additional voices
- Danny Cooksey as Klips
- Dee Bradley Baker as Clapper, some of Inkling boys, and additional voices
- Billy Crystal as Beako
- Jeff Bennett as Fins, and additional voices
- The name of the title "Splatoween" comes from a game Splatoon 2.