Barry Gilman was an accountant working for the Loughlin Family.
Barry was employed by three witches known as the Loughlins to be their accountant, but Barry was dishonest and scheming, and he decided to steal their money. This enraged the Loughlins. Gideon wanted to let Barry go, but his furious sister, Catriona, refused, and she cursed Barry, causing his stomach to become stuffed with money until he died from it.
His death drew in the attention of hunters Sam and Dean Winchester. A chance encounter between Dean and Gideon led to Dean chasing Gideon into the woods and fatally shooting him, but not before Gideon cursed Dean with a memory loss spell.
Despite Gideon's efforts, Dean was able to locate the remaining Loughlins and kill them all, thus driving the family to extinction and avenging Barry's death.