This is the amusing moment a playful science teacher teased a pupil napping at a desk in China.

Footage shows the man tiptoeing into the room after finding the schoolboy sleeping at a lecturer's desk at the Huanghe Science and Technology University in Zhengzhou, Henan, on September 27.

He proceeded to draw a funny sketch on the chalkboard of a cartoon character pointing at the boy in surprise, drawing giggles from the other students in the room.

When the boy finally woke up, the teacher walked to the door's entrance and mimicked the comical expression on the drawing he had made.

University students said the man was a beloved teacher at their school, and would sometimes sneak into classrooms to sit in on lectures.