The 19 year old, who is known to millions as Hogwarts bully Vincent Crabbe in the wizard franchise, was arrested after police pulled over his car and caught him in possession of several bags of pot.
His London home was subsequently raided by cops, who discovered the star was growing 10 cannabis plants. He was charged with illegal production and was handed 120 hours community service.
But new photographs show the actor shamelessly posing with his crop as he smoked the drug.
A pal tells Britain's The Sun newspaper, "Jamie is trying to look hard (tough) - like a drug baron surveying his empire. What a total idiot."
Waylett's character was written out of the series' final installment, Harry Potter and the Deathly Hallows, after the incident.