Oliver Rivers

For Irvin's ninth time seeing Puffs, he cosplayed the character with whom he most identifies: Oliver Rivers, the Puffs' mathemagician. Irvin went for his battle-hardened look from the Battle of Hogwarts: most notably, a shirt that is all torn up except for the surviving pocket protector.

Irvin not only got pictures with the real Oliver Rivers, Langston Belton, he even got to take a picture yelling at the real Ron Weasley from the show. After all, Irvin's been yelling "There's no need to be an asshole!" at Ron since at least 2007.

When Irvin returned to see Puffs in July 2018, after it had been announced that Langston Belton was leaving the cast soon, he reprised the costume. (It helps that it's a perfect July cosplay.)