Hermione Granger

In May 2010, Irvin's high school had an event called "Senior Nerd Day," for which Irvin dressed up as Hermione Granger (who is the ultimate nerd). For the first time when cross-dressing, Irvin didn't use fake breasts, because everyone knows that nerds don't have boobs. This caused an outcry from many offended nerds at his school.  But Irvin paid them no heed, and instead badgered them about joining SPEW.

He wore the outfit again the following November to a costume party at NYU, though this time with a skirt.

A full decade went by before Irvin felt the calling to reprise Hermione.  In October 2020, half a year into the coronavirus pandemic, Irvin's friends decided to partake in a wizard-themed scavenger hunt - which was beside the point for Irvin, who had a chance to do a group cosplay for the first time in many months.

They decided to be all of the basilisk's Petrified victims: Irvin would be Hermione, Angelica would be Penelope Clearwater, Maya would be Justin Finch-Fletchley, Sara would be Colin Creevey, and Amber would be the mind-controlled Ginny.  Each of them carried props representing how they'd been Petrified: a mirror, a camera, and Nearly Headless Nick.  Ginny also had the basilisk and the diary with her, and Colin even had the grapes he'd been sneaking down to Harry in the hospital wing.  Luckily, Irvin had all the pieces for everyone's costume - all they had to procure was a camera for Colin and a Nearly Headless Nick Funko Pop.  After some difficulty wrangling the angle of the basilisk in photos, they managed to get some really good photos that day.

Irvin wore Hermione again when his meetup group, the NYOP, had a discussion meetup all about Hermione on her birthday (Sept 19th) in 2023.  After all, with these types of discussions, it's always good to get a first-person perspective!