Chara's Origin

Undertale: Chara's Origin is a prequel to American/Australian/Canadian hand drawn Walt Disney film, Undertale based on Chara and Asriel's flashbacks.

Synopsis
Way before Frisk fell below in Mt. Ebott, his best friend, also known as the first human who fell into Mt. Ebott, Chara fell into the mountain. But let's see his flashbacks both on the surface and underground.

Cast
Michael Clifford as Chara, a 12-year-old(later 13) boy who fell into Mt. Ebott because his parents passed away in an accident. He had a cameo at the post credits scene.

Daryl Clifford as Daryl, Chara's biological father who passed away in an accident. He is based on Michael's real father.

Karen Clifford as Karen, Chara's biological mother who also passed away in an accident with her husband. She is based on Michael's real mother.

Justin Bieber as Bully, a bully from Chara's class who made fun of Chara for being retarical. His character appearance is Justin himself.

Selena Gomez as Susie, Chara's only best friend and classmate from the surface before he ran away. When the humans founded Asriel carrying Chara's body, she immediately told the villagers to stop fighting. Her character appearance is Selena herself.

Shawn Mendes as Asriel, Chara's adoptive brother who looked after Chara ever since he fell from the surface. He had a cameo in the post credits scene.

Sierra Deaton as Toriel, Chara's later adoptive mother who helped Asriel look after Chara. She had a cameo in the post credits scene though it was only her voice.

Luke Hemmings as Asgore, Chara's later adoptive father who is the king of all monsters. He had a divorce with his wife later in the film.

Alex Gaskarth, Avril Lavigne, Billie Joe Armstrong, Kelly Clarkson and Mark Hoppus as humans, they each had a cameo when Asriel is carrying Chara to the surface.

Harry Irwin as Flowey, Asriel's new form after he died and turned into dust. He had a cameo in the post credits scene.

Calum Hood as Frisk, Asriel and Chara's then adoptive brother and best friend who is the last human who fell into Mt. Ebott. He had a cameo in the post credits.

Liam Payne as Sans, a big boned brother of Papyrus. He also had a cameo in the post credits scene.

Ashton Irwin as Papyrus, Sans' joyful and optimistic brother. He also had a cameo in the post credits scene.

Trivia

 * It is based on Chara and Asriel's flashbacks