The origins of — and how to defeat — demons, doppelgängers and the ghost of urban legend, Bloody Mary.

I went through a ghost phase during junior high. My best friend, Kevin, had a little sister, Michelle, and the two of us would sneak out in the middle of the night to try various techniques to summon ghosts. One of those spells shows up in this roundup of Supernatural baddies: Bloody Mary.

For the record, while we sure freaked ourselves out, sneaking into the bathroom at midnight with a candle, chanting, “Bloody Mary,” we never did end up summoning a freaky wraith, alas.

RELATED: The Monsters of Supernatural S1, E1-3

S1E4: “Phantom Traveler”

Monster: Demon

Where it’s from: All over the world

Description: Demons come in all sorts of shapes and sizes — but they’re almost always horrifying distortions of nature. Beelzebub, for instance, is depicted as a giant fly, while another demon, Asmodeus, has the torso of a man, the leg of a rooster, the tail of a serpent and three heads (those of a sheep, a bull and a man spewing fire).

What it does: A demon’s favorite pastime seems to be possession. They like to take control of unsuspecting humans, causing them to act bizarrely. This can mean everything from being more aggressive, laughing maniacally or speaking in tongues to having supernatural knowledge or strength.

How to defeat it: In the Bible, Jesus spent a lot of time casting demons out of people. Since that’s not an option nowadays, it’s time to call in the exorcist. Entering a church or coming into contact with holy water really seem to piss off demons. Matthew 17: 21 says, “But this kind does not go out except by prayer and fasting,” so that might be a good idea for spiritual preparation. You really just have to be forceful with the suckers and be persistent in commanding them to leave. It’s a battle of willpower.

S1E5: “Bloody Mary”

Monster: Bloody Mary

Where it’s from: United States

Description: Light a candle, enter a bathroom, stare into the mirror and chant her name three (or 13) times. Legend has it, Bloody Mary will appear, but don’t expect a delicious brunch beverage. A ghostly woman is said to materialize, sometimes reported to be covered in blood. Some say she’s Queen Mary I, known as Bloody Mary for her propensity to burn Protestants at the stake. Others insist she’s a woman named Mary Worth, who died in a car crash.

If you really want to stir the pot, add this chant: “I killed your baby!” This is probably an allusion to Queen Mary’s “ghost baby.” She supposedly exhibited all the signs of pregnancy — she stopped menstruating, gained weight in her belly and felt nauseous in the mornings. But she never gave birth, and eventually her stomach shrank. (Historians think her intense desire for an heir resulted in a bizarre medical phenomenon called a “false pregnancy.”)

What it does: I’m not sure why anyone would summon Bloody Mary, except as a way to prove your bravery at slumber parties, as she’s said to scratch out your eyes upon appearing. Or she might just scream at you, strangle you or steal your soul.

How to defeat it: There doesn’t seem to be much about killing Mary once you’ve summoned her, but Dean and Sam wisely decide to destroy her connection to this world: the mirror she traveled through. Sounds like it’s probably worth risking seven years of bad luck.

S1E6: “Skin”

Monster: Shapeshifter / Doppelgänger

Where it’s from: Doppelgänger is a German word literally meaning “double walker.”

Description: Shapeshifters show up in legends from all around the world, the most common being werewolves. The baddie in “Skin” is the ultimate evil twin and only shifts into other human forms.

What it does: Seeing a dopplegänger is an omen of severe illness or death. The doppelgänger morphs into an exact replica of another human being, which it then kills and assumes its place. One clue that’s it’s not who you think it is: These creatures supposedly don’t cast a shadow.

How to defeat it: Kill it…before it kills you. –Wally