The Crooked Man is a vengeful spirit or tulpa that is said to go after those who despair. It is also said to be the entity that is featured in the famous nursery rhyme called There Was a Crooked Man. The crooked man is reputed to be the Scottish General Sir Alexander Leslie. He signed a covenant securing religious and political freedom for Scotland.
The "crooked stile" in the poem was the border between England and Scotland. "They all lived together in a little crooked house" refers to the fact that the English and Scots had at last come to an agreement, despite continuing great animosity between the two peoples, who nonetheless had to live with each other due to their common border.
As the Crooked Man, he appears as a scrawny and abnormally thin humanoid male, wielding a tattered umbrella, a withered dark red striped shirt and pants along with a small black fedora. His legs are misshapen and bent crudely as a result of a terrible accident or disease. His most frightening feature, however, is his wide monstrous grin, showing off rotted sharp teeth and deathly pale skin. He also seems to have round rim glasses that are stationed on the top of his fedora.
Being a vengeful spirit, the Crooked Man was once human named Alexander Leslie. However, in the midst of the worst chapter of his life, Leslie committed suicide by hanging himself and left for dead in his own house. Riddled with negative emotions that he last felt before he died, he became a vengeful and deadly spirit. After becoming a vengeful spirit (the Crooked Man), he becomes resentful and upon seeing anyone that enters his home, and immediately dislikes them.
His spirit haunts the very house he once resided in, and would not hesitate to harm or even call anyone that dares enter his house and make it their own. Moreover, he came to hate certain individuals or family members for being so much like himself, but staying happy. He tries to drive them to suicide, or kill them personally.