Dad always had a theory about Croatoan. He thought it was a demon's name, sometimes known as Deva, sometimes Resheph. A demon of plague and pestilence.
– Sam, 2.09 Croatoan
According to Wikipedia,
- "Resheph was a Semitic god of plague and war. He bore the head of a gazelle on his forehead and was an important member of the pantheon of Ugarit though not mentioned in Ugaritic mythological texts."
This is not the first time Mesopotamianism has cropped up in speculation around Supernatural's mytharc: there's a theory that Dean's Amulet is a Mesopotamian figure.