Imagine a week in which kids design and build their own fantasy world out of cardboard! That’s what happens in this adventure day camp. The kids build costumes, armor, weapons, and even their own castle out of cardboard, and then use those things to battle their enemies, the evil camp counselors (also wearing handmade cardboard armor). Adventures in Cardboard holds ten week-long camp sessions during the summer.
Redditor serablanche works at this camp each summer, as a referee and an evil character. He described it in a series of images, eleven photographs in all with explanations in the captions, which you can see at imgur.
That's serablanche behind the pop-tart shield at the top, and in this Black Knight getup, too.