In this animated adventure, the beloved characters from the classic Hanna-Barbera series embark on a new journey that delves into the origins of their friendship and the formation of Mystery Inc. The story follows Scooby-Doo and the gang as they face their most challenging mystery yet, involving a plot to unleash a ghost dog known as Cerberus upon the world. Featuring the voices of stars like Zac Efron, Amanda Seyfried, and Mark Wahlberg, the film combines humor and heart with a modern twist. Directed by Tony Cervone, this film offers a fresh take on the iconic franchise. For those interested, it can be viewed for free on 123Movies / Movies123.