Boreas is the recurring antgaonist in the "Pastoral Symphony" segment of the 1940 film Fantasia. He also makes a cameo appearance with recycled animation from the live-action/animated film So Dear to My Heart.
He is a two headed-cloud deity sent by Zeus. His task is to get rid of Bacchus, Jacchus, and his honorers by blowing them away. After Zeus falls asleep, Boreas is no longer needed and therefore isn't seen for the rest of the segment.