TheWrap has learned exclusively that Ariana Greenblatt will play young Velma, while Pierce Gagnon is set to voice young Fred.
Zac Efron is voicing the adult version of Fred, while Amanda Seyfried will play Daphne. Gina Rodriguez will voice Velma, while Will Forte will play Shaggy and Tracy Morgan will voice Captain Caveman — not part of the Scooby-Doo universe but a Hanna-Barbera character like the Scooby gang. Frank Welker will be voicing Scooby.
Tony Cervone is directing, while Chris Columbus, Pam Coats and Allison Abbate are serving as producers. Charles Roven, Richard Suckle, Dan Povenmire and Adam Sztykiel are executive producing.
In the film, the Mystery Inc. group will team up with other members of the Hanna-Barbera universe to save the world from Dick Dastardly.