Background
Mosteller was born in New York City, New New York
Mosteller was born in New York City, New New York
The youngest of five children to Rosa Mosteller (née Cedarbrook). He has an older sister named Rose Josie Mosteller (born July 10, 1996) Rose Mosteller is also an actress. He has another older sister named Maisey Hattie Mosteller (born July 14, 1996) He has one more older sister named Josie McKenna Mosteller (born July 1, 1996) He spent most of his early life and childhood in Scotland and then moved to Colorado.
He started acting at the age of three.
In 2011, he started filming for Judy Moody and the Not Bummer Summer. He played the role of Stink.