A tulpa is, in Tibetan mysticism, a being or object which is created through sheer willpower alone. In other words, it is a materialized thought that has taken physical form (a thoughtform).
The concept was brought to the West in the 19th century by Alexandra David-Neel, who claimed to have created a tulpa in the image of a jolly, Friar Tuck-like monk which later developed a life of its own and had to be destroyed. David-Neel has been cited by Wells (2006), follow website metalink in notes or references.
Many authors and artists have since used tulpas in their works, both in the context of fiction and in writing about mysticism. Horror author Clive Barker, for example, envisioned his famous "Candy Man" killer to be nothing more than a myth gone terribly awry in his original story.
The boys came upon a tulpa in Richardson, Texas. Two kids had made a house look haunted, painted symbols and such on the walls, but they'd inadvertantly painted a symbol, from the girl's theology texbook, that could create a tulpa. When two computer geeks took pictures of the house and put it on their website about haunted places, all the web surfers that came to the site, looking at the symbol and thinking about Mordachai, brought the thing to life. The tulpa was named Mordachai Murdoch and the story changed several times until the boys tried to make it so he would be fatally afraid of firearms with iron rounds. It didn't work, however, and Dean just ended up burning the whole damn house down, hoping that it would destroy the spirit.