An elementary school math assembly quickly transformed into a long-awaited reunion between a fourth-grader in Columbia, South Carolina, and her father, a returning soldier.

Staff Sgt. Joel Spector, who just wrapped up a nine-month tour of duty in Afghanistan, made a surprise visit to his daughter’s school on Wednesday, according to local TV station WISTV.

Spector dressed up as the Piggly Wiggly Pig and stunned the room full of children, especially his young daughter, when he took off the head piece.

To keep the homecoming a surprise, students at Saint Joseph Catholic School had been told the assembly was being held to recognize classmates who performed well in math, the station reported.

 WISTV in South Carolina contributed to this story.