Trial starts for girls claiming made-up internet monster told them to stab classmate 19 times

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

WAUKESHA, WI-- It may be scaring all the kids right now but there's another fictional character parents should probably look out for.

He's got four long limbs, a blank face, and if that's not scary enough he allegedly inspired two girls to stab their classmate 19 times.

On Monday, the jury listened to opening statements in what is known as the Slender Man trial.

Back in 2014, then 12-year-old Anissa Weier and Morgan Geyser allegedly carried out a plan to attack Payton Leutner in a wooded park in Wisconsin.

The girls both claim they only did it to please the made-up internet monster Slender Man. They also believed he'd kill their parents if they didn't commit the crime.

Both suspects, now 15-years-old, are being tried as adults for attempted first-degree intentional homicide.

But Weier's lawyers claim his client suffers from depression, delusional disorder and can't separate reality from fantasy. If jurors buy that story, she'll face at least three years at a mental hospital. If not, then she could be looking at 10 years or more behind bars.

As for Geiser, the one who allegedly stabbed Leutner 19 times, her trial begins in October.