Chilling interrogation recordings of the suspects in the so-called Slender Man attempted murder have been released by police.
Two Wisconsin girls, both aged 12, are charged with stabbing their friend, Peyton Leutner, 19 times and leaving her for dead in the woods.
Miraculously she survived and managed to raise the alarm.
Tapes of the girls' interrogation show both blaming each other for the attack which they claim was carried out to appease the fictional Slender Man.
One says: "I was excited because I wanted proof that he existed because there were a bunch of skeptics out there saying he didn't exist.
The other adds: "I was afraid of what would happen if I didn't ... I didn't want to find out what would happen if we didn't."
Psychologist Deborah Collins testified to a preliminary hearing that she has interviewed one of the girls several times and concluded she honestly believes Slender Man exists.
"(Her belief) hasn't wavered and it's been unyielding to a rational perspective," Collins testified.
Collins also testified that the girl told her she uses Vulcan mind control to keep negative emotions at bay and believes Harry Potter villain Lord Voldemort visits her when he's not away on business trips.
A private detective working for the defense testified he discovered more than 60 drawings of Slender Man in the girl's bedroom.
Many of the sketches included notes such as "not safe even in your house" and "he is here always." One drawing depicted a girl lying on the ground and a person standing over her with the message "I love killing people" written over the figure.
The detective went on to say he found more than a half-dozen Barbie dolls in the bedroom that had been marked with Slender Man's symbol. Some were missing their hands and feet.