The Spectrals is a 2017 family, fantasy film based on the Harvey Comics characters Casper the Friendly Ghost, Wendy the Good Little Witch, Hot Stuff the Little Devil, Richie Rich, and Baby Huey. The film is a crossover of the Richie Rich films: Richie Rich (1994) and Richie Rich's Christmas Wish (1998), the Casper films: Casper (1995), Casper: A Spirited Beginning (1997) and Casper Meets Wendy (1998), and Hot Stuff (2016). It's loosely based on the 2009-2010 three issue comic book miniseries, Casper and the Spectrals,; however it features more characters in the Harvey Universe aside from the Trio: Casper, Wendy and Hot Stuff and has a different antagonist.
When the sinister warlock known as Desmond Spellman has manage to escape from the Mytstic Abyss after the events in Casper Meets Wendy, and is now recruiting an team of witches, a young spiritual wizard name Dewon a form team of three supernatural beings: Casper the Friendly Ghost, Wendy the Good Little Witch and Hot Stuff the Little Devil of stopping the warlock once again from whatever plan he has in store.
- Collin Dean as the voice of Casper McFadden the Friendly Ghost - the ghost of a dead 12 year old who has been living in Whipstaff Manor at Friendship Maine with his uncles: the Ghostly Trio, and two human friends: Kathleen "Kat" Harvey, and Dr. James Harvey. He has been chosen along with Wendy the Good Little Witch, his old time friend, and Hot Stuff the Little Devil by Dewon to form a group. Due to his good heart, and willingness to help others, Casper was given a power that was contain in a chest by Dewon, so it will aid him in his fight against Desmond, and has become team's leader; however, Casper has problems of getting along Hot Stuff, due to his mischievous nature.
- Sabrina Carpenter as Wendy the Good Little Witch - a young witch who has become the greatest witch of all after the fall of her nemesis Desmond Spellman and for befriending Casper century ago. She and Casper have been reunited when they along with Hot Stuff the Little Devil have been assigned on a mission by Dewon, when her old enemy has returned. Of the three, she is quite the voice of reason. She also has a rivalry with Desmond's niece, Wildcat.
- Tyrel Jackson Williams as Hot Stuff the Little Devil - a demon child with a heart, but has a temperment especially after losing his friendship with Amber Whitmire, and is force to remain a demon, even when he manage to save her and her family. He was chosen by Dewon along with Casper and Wendy to help take on Desmond Spellman, to which he reluctantly agree to. His attitude can be shown as a strength and a weakness when he gets reckless. This caused an uneven clashed between him and Casper, as Hot Stuff shows a disdained for Casper's leadership due to his friendly persona.
- Jace Norman as Richie Rich - the world's richest kid who have saved his home from a greedy CFO, and has set things right on Christmas, will now discover that he lives in a world where they're supernatural beings after his family scientist Professor Keenbean and students were kidnap by a group of witches led by Desmond Spellman for plans of his own. Richie insist on joining Casper, Wendy and Hot Stuff in order to save his Professor from Desmond, and with the help of his computer skills in being able to track the whereabouts of Desmond, he has shown to be an helpful member of the team.
- Jonah Hill as Baby Huey, motion caputure - a science experiment for Professor Keenbean whose original attampt was to grow his wings again, but after the professor was taken by the witches, they accidentally used their magic on Huey and turned him into a giant infant duck.
- Ron Paulson as the voice of Baby Huey
- Davis Cleveland as Dewon - a young wizard who wants to see the good side of things especially those of the haunting supernatural, to which he sees with Casper, Wendy and Hot Stuff. He finally gets that chance when he discovered that Desmond Spellman has escape, and assembled the Trio to band together as a symbol of hope to stop the evil warlock.
Desmond Spellman and His Witch Army
- Benedict Cumberbatch as Desmond Spellman - the main antagonist of the film. After his defeat in Casper Meets Wendy, the warlock manage to survive the incident of the Mystic Abyss, and with the help of a group of witches, he has a determination to continue his path for greatness, and will stop at nothing until he gets it.
- Lizzy Greene as Wildcat - Desmond's niece, and Wendy's rival. She has shown to have a fixation on Casper.
- Mark Addy as Professor Keenbean - the Riches' family scientist and inventor, who has become a victim for Desmond as he is force to do his bidding.
- Forest Whitaker as the voice of Kibosh - the Godfather of Ghouls who mentor ghosts in how to scare others. He has shown to have a rivalry of Desmond at some point in time. The rivalry has come to a conclusion when Desmond has kidnap him for his own personal desires.