Liam Hooper is shooting a $1,600 (£1,000) film for his A-Level exams in the U.K., and tried his luck by sending off the script to the Night at the Museum star.
And the 17 year old was stunned when Coogan replied, asking for a cameo in the project.
Hooper tells Britain's Daily Mirror, "I thought he might like my tongue-in-cheek script. But I never thought he'd agree to take part. All I can say is he appears at a pivotal moment."