Dazhbog is Slavic god of Sun and fire, son of Svarog and chief god of Serbs. He was also considered and as ancestor of all Slavs, because at this time it was rare for grandson/granddaughter to meet grandpa. He was imagined as man wearing either wolf or bear fur who becomes older at winter and young at summer.
His totem animal was wolf, therefore wolf was sacred animal and killing it was considered great sin. Wolves were considered as messengers of Dazhbog, while he himself could shift into white wolf. There was belief that each winter he is visiting people's homes and gifting gold to good ones. That belief passed into Christianity, especially in Serbia, and visitor was called Položajnik.
During Christianization, his cult was exchanged with cult of Saint Sava, while Dažbog became lame Daba - the most powerful demon in Hell. Reasons why he was demonized are various, possibly because his cult was the strongest in Serbia or because he was considered also as god of Nav - Slavic underworld and world of dead.