This is a term that we give to someone who looks like you, and that upon seeing them is said to give you bad luck.
What is a doppelganger?
Arachnophobia, a common phobia among flies, say.
What is the fear of spiders?
A2+B2=C2. Helpful for finding the lengths of a triangle.
What is the Pythagorean Theorem?
"The Power of Christ compels you!"
Who are Father Merrin and Father Damien?
What is The Exorcist?
This individual was known as "The Killer Clown".
Who is John Wayne Gacy?
This object, when knocked over or brazenly wasted, is said to bring bad luck.
What is salt?
Thalassophobia, a common phobia among Jordan, say.
What is the fear of open bodies of water?
A common conjunction, starting with the letter "a".
What is "and"?
"Here's Johnny!"
Who is Jack Torrance?
What is The Shining?
This individual was known to drive a "slug bug".
Who is Ted Bundy?
This comes as a consequence of breaking a mirror.
What is seven years of bad luck?
Hippopotomonstrosesquipedaliophobia, a common phobia among those that might be more linguistically challenged.
What is the fear of long words?
This is the name of the main character in To Kill a Mockingbird.
Who is Scout Finch?
"I ate his liver with some fava beans and a nice Chianti."
Who is Hannibal Lector?
What is Silence of the Lambs?

Who is the Zodiac Killer?
This is the reason why we we say bless you after a sneeze.
What is attempting to avoid the Devil entering your body to replace your soul?
Tryptophobia, a phobia among just about everyone, say.
What is the fear of lots of holes?
SN, a chemical element on the fifth row of the periodic table.
What is Tin?
"Would you like to live... deliciously?"
Who is Black Phillip/ Satan?
What is The Witch?
This individual was an aspiring real estate mogul, known for his hotel that was filled with killing contraptions.
Who is H. H. Holmes?
This is considered to be an insult to the Sun God.
Why don't we open an umbrella indoors?
Autophobia, a phobia commonly seen from an extrovert, say.
What is the fear of being alone?
The only American President that has won two elections, non-consecutively.
Who is Grover Cleveland?
"I'm scared to close my eyes. I'm scared to open them."
Who is Heather Donahue?
What is The Blair Witch Project?
This rather "bricky" individual had 6 known victims including Annie Chapman and Elizabeth Stride.
Who is Jack the Ripper?