In a live-action sequel to the Ultimate Spider-Man episode, Halloween Night at the Museum, Jessie Prescott and her kids find themselves in a predicament when an evil group called, the Sons of the Serpents attack the Hotel, some of the kids suddenly disappear when an item causes them to separate them into different places, and Jessie teams up with several of the Avengers and the rest of Marvel’s heroes.
- Jessie Prescott (Debby Ryan) - when the Hotel was attached, Jessie seeks to find the kids, as she discovers from Doctor Strange that a map shows Zuri in Wakanda, Emma in space with Captain Marvel, Luke with Vision in the Avengers base and Ravi is in San Francisco with Ant-Man, she is given by Doctor Strange, the Real Sword of Excalibur from one of the items in the Sanctum, as the one in the museum is replaced by a fake one that Morgaine le Fey removed to replace it with the Real one when King Arthur died
- Emma Ross (Peyton List) - is with Captain Marvel in space when she is the pilot.
- Luke Ross (Cameron Boyce) - is with Vision in the Avengers base, hidden from the rest of the Avengers
- Ravi Ross (Karan Brar) - is with Ant-Man in San Francisco, studying the Vibranium.
- Zuri Ross (Skai Jackson) - is Black Panther in Wakanda, acting as princess of Wakanda, while Shuri is acting Queen
- Avengers: help Jessie find the kids
- Tony Stark/Iron Man (Robert Downey, Jr.) - Acts as the head Principle.
- Steve Rogers/Captain America (Chris Evans) - Shows the kids history.
- Thor (Chris Hemsworth) - helps them with understanding languages.
- Bruce Banner/Hulk (Mark Ruffalo/Lou Ferrigno) - acts as a teacher of anti bullies.
- T’Challa/Black Panther (Chadwick Boseman) - tells Jessie that Zuri is princess of Wakanda, when Shuri is acting queen, she does what she wants
- Vision (Paul Bettany) - keeps Luke hidden from the Avengers playing video games and having snacks, as he keeps his hands behind his back to move any direction showing Luke crawling so they wouldn’t see him
- Doctor Strange (Benedict Cumberbatch) - helps Jessie find the kids by giving her a map that shows their locations
- Carol Danvers/Captain Marvel (Brie Larson) - finds Emma in space in a Space Station.
- Guardians of the Galaxy: help Captain Marvel take Emma home
- Peter Quill/Star-Lord (Chris Pratt)
- Gamora (Zoe Saldana)
- Drax (Dave Bautista)
- Rocket (Bradley Cooper)
- Groot (Vin Diesel)
- Scott Lang/Ant-Man (Paul Rudd) - finds Ravi in San Francisco in Hank Pym’s lab, as he studying the Vibrainium.
- Hope Van Dyne/Wasp (Evangeline Lily) - helps Scott babysit Ravi
- Hank Pym (Michael Douglas) - shows Ravi around the base
- Wakanda Royal Family:
- Shuri (Letitia Wright) - acting Queen of the Country when T’Challa is away, she even makes Zuri temporary princess of Wakanda
- Dora Milaje:
- Okoye (Danai Gurira)
- Ayo (Florence Kasumba) - threatens Jessie when she tries to enforce Zuri by grounding her by saying the same thing she said to Black Widow, “Move or you will be moved”
- Nick Fury (Samuel L. Jackson)
- Clay Quartermain (Bruce Willis) - Acts as Nick's would be successor if anything happens to him.
- Team Coulson:
- Phil Coulson (Clark Gregg) - reappears since the Season 2 finale of Ultimate Spider-Man, he even states to Fury, "What were you thinking, I've been away for too long", when he enters the room.
- Melinda May (Ming-Na Wen)
- Daisy Johnson/Quake (Chloe Bennet)
- Leo Fitz (Iain de Caestecker)
- Jemma Simmons (Elizabeth Henstridge)
- Michael Peterson/Deathlok (J. August Richards)
- Bobbi Morse/Mockingbird (Adrianne Palicki)
- Shanna the She-Devil (Charlize Theron) - Queen of the Savagelands with her husband Ka-Zar.
- Christopher Powell/Darkhawk (Tom Cruise) - a vigilante who rivals Captain America.
- Sons of the Serpents: the group that attacks the Hotel, for secrets of S.H.I.E.L.D.
- Son 1 (Daniel Wu) - the main antagonist, the head of the Son of the Serpents, his goal is to gain the secrets of Vibrainum, which he was searching for in the Hotel, so he can use it to build into a Weapon.
- Son 2 (Jemaine Clement) - the secondary antagonist, who serves as the Hunter.
- Son 3 (Issac Singleton Jr.) - the tertiary antagonist, He is the muscle of the group.
- Son 4 (David Kaye) - the quaternary antagonist, He is the science genius.
- Daughter 1 (Gina Torres) - the quinary antagonist, she is the hypnotist of the group.
- Invisible Touch - by Genesis, played during ???
- Hungry Like the Wolf - by Duran Duran, during ???
- Can’t Fight This Feeling - by REO Speedwagon, during ???
- This is a sitcom special that contains a laugh track when jokes are played.
- This special is a sequel to the Ultimate Spider-Man episode, Halloween Night at the Museum.