This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Khalkotauroi (Greek)
Khalkotauroi, also known as the Colchis Bulls, are mythical creatures that appear in the Greek myth of Jason and the Golden Fleece. The Khalkotauroi are two immense bulls with bronze hooves and bronze mouths through which they breathe fire. In the Argonautica, Jason is promised the prized fleece by King Aeetes if he can first yoke the Khalkotauroi and use them to plough a field.
He should then sow it with dragon's teeth. Medea, Aeetes' daughter, had fallen in love with Jason, and offered her assistance; she gave him a potion which protected him from the fires of the Khalkotauroi. He then yoked them and passed the task he was given. The Khalkotauroi were a gift to King Aeetes from the Greek gods' blacksmith, Hephaestus.