12-year-old surfer-boy Osmo and his dad move from the beach to live with their distant family in the quirky town of Winterton, where it snows all-year-round and monsters are strictly forbidden. Osmo and his plucky cousin Rita form an unlikely friendship with a towering yellow yeti called Gustav, who is an unstoppable giant goofball. Together, the fearless cousins help keep Gustav hidden from Osmo's monster- loathing uncle, Mayor Chrome, while exploring all the offbeat, laugh-out-loud adventures their frozen home has to offer.