There's a Monster on my t-shirt and I dunno what to do about it

My dear friend, the Green Fairy (yes, that IS her name), came by the Nilsalon today and bought one of my shirts. The collection is called "There's a Monster on my t-shirt and I dunno what to do about it." All the shirts are unique, none is ever sold twice. The back is not empty either. But there'll be a post about my shirts soon anyways, and I don't wanna tell you everything up front.

Just know that The Green Fairy is as magical as she sounds!