Blue Öyster Cult Logo

Episode(s): Hell House
Although usually recognised as the logo of heavy metal band Blue Öyster Cult, the symbol traditionally belongs to Kronos, the king of the Titans from Greek Mythology and is also the alchemical symbol for lead - one of the heaviest metals. It was used as one of the symbols drawn on the walls of the Hell House, probably copied from the cover of a Blue Öyster Cult LP.

Coptic Cross

Episode(s): Faith
Sue Ann LeGrange was using a Coptic Cross to control a Reaper. In Christian mythology, the cross represents Christ's crucifixion and resurrection, which explains why it was being used in connection with a reaper.

Devil's Trap

Episode(s): Devil's Trap, Crossroad Blues, Born Under a Bad Sign, All Hell Breaks Loose Part Two, The Magnificent Seven, Bad Day at Black Rock, Sin City
The Devil's Trap is primarily used to control demons. When they step onto or under a drawn trap, they are powerless and unable to move. Once trapped, they can easily be exorcised. In addition, a Devil's Trap can be drawn or engraved onto an item in order to protect it from demons. The first image is the standard trap that is used for demons. The second image is a variation that Sam drawns on the trunk of the Impala in order to make it into a safebox that cannot be accessed by demons.

Pentagram

Episode(s): Pilot, Dead Man's Blood
First seen when worn by Amy while she talks to the boys about her boyfriend having gone missing. She says that she wears it to scare her parents with "all that devil stuff". This is a common misconception about the symbol which is traditionally a pagan protection symbol. However, certain malevolent practices, such as Satanism, have been known to use the symbol for their own purposes, usually inverting it so that the fifth point is downwards. It symbolises the four elements (earth, air, fire, water) plus the addition of spirit as the fifth point. There is also a pentagram etched onto the butt of the Colt.

Sigil of Azazel

Episode(s): In My Time of Dying
Used by John Winchester to summon the Yellow-Eyed Demon. John's use of the sigil indicates that he was aware of the demons true identity as Azazel.