Carbon Costume

On the CW show Supernatural, Kevin Tran (played by Osric Chau) is originally introduced as an extremely intelligent high school student who is dedicated to maintaining straight As.  However, he is soon transformed into a prophet of God, and helps Sam and Dean by translating tablets related to the Leviathans, Demons, and Angels.  Kevin is eventually killed and now roams the Earth as a ghost rather than return to Hell.  Finding a Supernatural-style tablet can be difficult and expensive, but you could DIY your own stand-in with a slate charcuterie board or tile and a fine tip chalk marker.