A Jubokko was a kind of hematophagic yokai in the form of a twisted tree that was born from centuries of continual bloodshed, which corrupted the tree into a demon that would hunt down any who strayed near them - grabbing them in twisted branches and dragging them into a deadly embrace where sharp spikes would impale the victim and the Jubokko would consume their blood.
The victim's broken body would then be dropped to the ground by the Jubokko's roots and as such the monster could always be detected by the sight of defiled ground around its roots - covered in the blood, bones and rotting corpses of those it had previously killed.