This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Cikavac (Serbian)
Cikavac is a mythical creature in Serbian mythology, imagined as a winged animal (a bird) with long beak and a pelican-like sack. A cikavac could be acquired by taking an egg from a black hen, which would then be carried by a woman under her armpit for 40 days, during which time one would not confess, cut nails, wash face or pray.
The cikavac would then suck honey from others' beehives and milk of others' cattle, and bring it to the owner; it would fulfill any owner's wish, and also enable its owner to understand the animal language. However, since cikavac itself wasn't able to create these things out of thin air, every once and a while it would actually steal them from it's owner's neighbors.