Christopher Reeve’s son Will revealed to People magazine ahead of the release of the upcoming documentary “Super/Man: The Christopher Reeve Story” that Robin Williams was the first person who visited his father in the hospital after Reeve was paralyzed from the neck down. Williams also managed to make Reeve laugh for the first time since the accident by pretending to be a Russian proctologist.

“Robin was dad’s best friend, and you show up for your friends,” Will said, adding that Williams and Reeve called each other “brother.”

“Our dad and Robin had a singular bond,” Will added. “They had a friendship that someone should make a movie about, but what shone through in that was just their love and respect for each other, and that never wavered. … No one was better at showing up with love and with the right dose of humor than Robin Williams and his wife Marsha,...