Croatian Tales of Long Ago - Črt

Having created Heaven and Earth, all in Heaven and on Earth, Svarog looked at his work. Relishing the sunlight, he looked at the vast dusky forests, healthy grasslands, deep blue sea dotted with islands and powerful water torrents. His shadow danced behind him. It wriggled and squirmed until she broke away from Svarog's body and soaked into the ground beneath him. Thriving hidden from the sunlight, she wished to rule an empire as large and as powerful as Svarog's. However, she could not leave her black sanctuary. Thus arose Črt, her incarnation. It was a creature black like her, but delicate enough to change shape and strong enough to leave her underground sanctuary. He could embody every human fear and every being that stubbornly resisted natural and human laws. He went hunting for the souls of damned people and their riches.
Thus, in the end, an army of demons was created. When the Darkness felt strong enough, she challenged the God of light himself. She kidnapped the one Črt longed for the most and feared the most, Zora, the light-bearer.

Croatian mythology set continues with a donkey. But do not be fooled there is someone hidden behind its eyes.