In Belgian folklore, Kludde, or Kleure, is a malicious spirit or goblin which roams the Flemish countryside.

Kludde usually appears in the shape of a monstrous Black Dog, sometimes winged, that walks on its hind legs. It can also assume the shape of a huge, hairy, black cat, a half-starved horse, a frog, a snake, a bat, or a large black bird such as a crow or raven. The creature also takes on more unusual forms for a road bogie, such as that of a tree, a shrub, or even a human being. Because its appearance was amorphous and it could take such a variety of shapes, Kludde's true form was unknown, if it even had a true form. It was sometimes described as a water sprite or goblin, and other times as a demon that had escaped from Hell, a werewolf, or even a manifestation of the Devil.

Kludde was a shapeshifter, and so could take on many different forms, depending on what it wanted to do or how it intended to play its pranks on humans. It could disappear or reappear at will to surprise victims and run at supernatural speeds to catch up with people who tried to run away from it, making escape impossible. When attacking, it could change its own height and weight. Whatever form it was in, Kludde was capable of speech.

In the tradition of similar entities such as Puck and the Kelpie, Kludde was a trickster spirit, although its tricks ranged from simple mischief to outright murder. Kludde was said to hide in the twilight of dawn and sunset and attack innocent travelers.

Travelers would listen for the only sound which betrays that Kludde is in the vicinity: the rattling of the chains with which the spirit is sometimes covered. The faster one walks, the faster this monster follows, even able to outpace a victim who ran in a zigzag. It could also be identified by blue flames that floated in front of it or were in its eyes.
As a horse, Kludde would sometimes offer travelers a ride and, once they were mounted, would go at a breakneck pace, leading the victim on a terrifying ride. In this form it was little more than a prankster, since it would release its victims by throwing them into a pool of water and laugh at their misfortune, leaving them humiliated and angry but otherwise unharmed.

At other times it would drive healthy horses from stables and viciously attack grooms who approached it. In some stories, Kludde is depected as less murderous and was more of a trickster than a genuine threat. It sometimes changed itself into a tree to confuse travelers who relied on landmarks, or a shrub to trip people up. In other cases it would even take human form, entering homes and wastefully burning the firewood of the people whose houses it visited.

At other times it would change into a sickly animal and trick people into carrying it on their backs, at which point it would grow heavier to the point of discomfort, exhaustion, or even death. Kludde was at its most malicious in the form of a black dog, as in this form it was capable of doing real harm. It would walk alongside people walking on a road or path before jumping onto their backs and crushing them, much like Oschaert. Sometimes it would kill the victim, but at other times was satisfied by the fear it created and disappeared, leaving the person shaken but unharmed. At other times it would stand on its hind legs, rising up until it could tear out a victim's throat.

Only the coming of daybreak or the sound of church bells could drive off Kludde and save the victim from a gruesome death.

Source: www.monstropedia.org/