Lord Dattatreya is referred to as बालोन्मत्त्पिशाच in many scriptures.
The word itself is made up of three words
1) बाल- Literally meaning the child (It is a jeevanmukta lakshana)
2) उन्मत्त- Meaning the one who acts like a enthusiastic crazy person (Jeevanmukta Lakshana)
3) पिशाच- Demonic , It is a special type of bhoga-yoni created for people with bad karma.
A pisacha is one with deteriorated human body which is bleeding from many sides and is decomposing, they eat humans and other dead animals, they have very big nails and totally black skin and a continuous bad odour from their body.
My question is why is lord dattatreya is called a पिशाच
he is jeevanmukta and an avatar of lord Vishnu, so how can he be in pishacha yoni which is meant for people with heavy load of bad karma.