Organizers said one of their cosplay winners from last year, who also served as a judge this year, allowed them to showcase her costume in their collection.
While it is possible that a member of the team may have removed it, organizers are afraid that it was stolen.
They are offering a $1,000 reward for the missing prop.
They said the cosplay winner put hundreds of hours into the costume, so they are hoping a fan may have found the helmet and recovered it.
“We’ll look at security cameras when normal business hours resume but your help in the meantime would be greatly appreciated,” organizers said in a release. “I’m sure I don’t have to tell you how upsetting this is for the creator, and our hearts are broken for her. Please help us make this right.”
If you have any information about the missing prop, email firstname.lastname@example.org.