Flying Graysons

The Flying Graysons were a team of activates featured in Robin/Nightwing/Batman comics. 
It consisted of Mary Grayson, John Grayson and their son, Dick Grayson. They performed for Haly's Circus, but tragically, Mary and John were murdered by Tony Zucco. In the aftermath, Dick was adopted by Bruce Wayne and became his sidekick Robin and, later, Nightwing.