Molly Monster is going to have a sibling soon, but his good friend Edison is a little bit jealous and worried she might forget about him. When Molly's parents have to travel to the Island where monster parents hatch their eggs, Molly is not allowed to go because she is too young, nonetheless she decides to reach them on her own as soon as she realizes they missed to bring her sibling's gift with them.

A new film about Molly Monster and her best friend Edison. Christmas is approaching, and all the monsters in monster land are getting ready for the big day. One night, Molly and Edison find out about the mysterious Christmas monster. They set off on a journey to find him. Will they succeed? And will they make it back home in time for the celebrations?