This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Kobalos (Greek)
The kobalos was a sprite from Greek mythology, a mischievous creature fond of tricking and frightening mortals. The kobaloi were companions of Dionysus and could shapeshift as Dionysus in the guise of Choroimanes-Aiolomorphos. According to one myth, they robbed Hercules while he slept.
He captured them in revenge but took pity on them when he found them amusing. In one version of the myth, Herakles gave them to the Lydian queen Omphale as a gift. The kobaloi were thought to live in Euboea or near Thermopylae. Parents used tales of the kobaloi to frighten children into behaving.