Leo is a cantankerous seventy-four-year-old lizard who has spent decades trapped in the terrarium of a Florida elementary-school classroom alongside his turtle companion. On discovering he has only a year left to live, he plans to escape to see the outside world, but ends up entangled in the fears and anxieties of the students in his care each week, including the arrival of a fearsome substitute teacher. An animated musical comedy voiced by Adam Sandler, it is a tender, open-hearted tale about growing up, the passage of time and the unexpected lessons learned just as the clock runs down.