Ian

Ian runs a shop called Ian's Herbal Remedies in Ogden, Utah. His shop also serves as a haven for hunters, as noted by the special "hunter's signs" on the door. His shop is used by hunters to procure certain ingredients and presumably other paraphernalia for hunting and spells. Sometime in the past, he helped Sam and Dean out while they were hunting a witch.

History
When Castiel realizes Gadreel is moving north, believing he will end up next in either Auburn or Ogden, Utah; Dean tells Cas to take Auburn, while he and Sam take Ogden. Dean remembers that they had worked a case in Ogden, with Sam remembering they got help from Ian. As Sam and Dean race to Ogden, Gadreel enters his store looking for griffin feathers and fairy bones, telling he knows about the hunter's signs on his door, which lulls Ian into trusting Gadreel. By the time Sam and Dean arrive, they find Ian's dead body hanging on a door with his eyes burned out.