The voice cast for Supernatural Summer

THE EQUESTRIA GIRLS:
Tara Strong as Twilight Sparkle
Cathy Weseluck as Spike
Rebecca Shoichet as Sunset Shimmer
Andrea Libman as Fluttershy
Shannon Chan-Kent as Pinkie Pie
Tabitha St. Germain as Rarity
Ashleigh Ball as Rainbow Dash
Grey DeLisle Griffin as Applejack
Kelly Sheridan as Starlight Glimmer
Kathleen Barr as Trixie Lulamoon

THE GRIMWOOD GIRLS:
Chloë Grace Moretz as Sibella Dracula
Kari Wahlgren as Phantasma
Kyla Rae Kowalewski as Tanis
Nika Futterman as Winnie Werewolf
Vanessa Marshall as Elsa Frankenteen
Diedrich Bader as Matches
Ashly Burch as Enid Meetle
Kate Micucci as Galactica
Hynden Walch as Lagoona Black
Myrna Velasco as Minimal

SPECIAL GUEST STARS:
Justin Timberlake as Henry
Selena Gomez as Zoe
Tom Holland as Jason
Julia Roberts as Tahlia
Dwayne Johnson as Leonard
Robert Downey Jr. as Igor
Kevin Hart as Slither
Alec Baldwin as Frank
John Michael Higgins as Connor
Dwight Schultz as Morgan
Joey King as Lucy, a powerful sorceress and Zoe's younger sister.
Chris Pratt as Walter, a human cyber hacker who helps the Rainbooms and the Grimwood Girls for the adventure.
Ryan Reynolds as Mayor Harvey Sanpedro, the centaur mayor of Monsterdom.
Lucy Liu as Cleo, Lucy's talking pet - a black cat.
Steven Jay Blum as Luke Karloff / Brian Lugosi, Karloff is a publicist who tries to make bad publicity for the Grimwood Girls but no one believes him. Lugosi is a presumingly deceased mad scientist, who tried to escape from jail 3 years ago via wingsuit, but ended up plummeting into the ocean in the process.
Mark Hamill as Lance Worthington, a famous (and somewhat cocky), human book writer and book keeper that the Grimwood Girls have a collection of copies of his books.
J.K. Simmons as Colonel Calloway, the former mentor of the Calloway Cadets.
Hannah Waddingham as Miss Grimwood, the former mentor of the Grimwood Girls.