A mystery donor has bought a billboard of Batkid so the 5-year-old superhero can watch over Gotham city at all times. Batkid, or 5-year-old Miles Scott, touched hearts worldwide in November when he became Batman for a day. Miles is in remission from leukemia and the Make-A-Wish foundation organised the unique experience. Patricia Wilson, executive director of Make-A-Wish Greater Bay Area, tweeted a photo of the giant sign after coming across it on Thursday near the San Francisco-Oakland Bay Bridge.