Miguel Martinez was playing hide-and-seek with friends on the museum grounds at about 3 a.m. Saturday when he apparently ran into the statue, university spokesman Chris Cook told the Lubbock (Texas) Avalanche.
Martinez's mother, Judith Leseburg, told KCBD-TV, Lubbock, her son -- one of nine children in the family -- had been spending the night with a friend and "just happened to trip over" a light.
"I guess he lost his balance and he went straight down on one of the horns," Leseburg said. "It's hard for all of us. No mother expects this to happen to their child."
Martinez's friend, identified only as Jeremy, said the victim "was like a big brother to me."
"I just laid there beside him. I put my jacket over him and just held him tight and told him I loved him," Jeremy said.