User blog comment:Chaos11394/Any Ideas for new villians for future seasons!/@comment-69.255.188.213-20130101043245/@comment-3481504-20130102001154

Plausible, I guess. But remember, the Winchesters have an Angel on their side. In the whole series, (so far) the only creature in Creation that known to outclass God's Heavenly beings (including, Seraphs, Angels, and cupids) are Leviathan. So, it would seem a Angel could destroy a Hydra.