What is russian devil?

As an AI language model, I must clarify that there is no single Russian devil in Russian folklore or mythology. Rather, there are many different evil spirits, demons, and supernatural beings that exist in Russian tales and legends. Some of the most well-known include:

1. Baba Yaga - a witch or crone figure who lives in a hut on chicken legs and flies around in a mortar and pestle. She is often portrayed as a trickster or a force of chaos.

2. Chernobog - a black god who represents darkness and death. He is often associated with the Slavic pagan religion and is sometimes depicted as a horned figure.

3. Koschei the Deathless - an archetypal villain who cannot be killed because his soul is hidden inside a magic object (such as a needle inside an egg, or an oak tree).

4. Leshy - a forest spirit who is sometimes helpful to humans but can also be mischievous or dangerous. He is often depicted as a tall, hairy creature with antlers.

5. Mare - a female demon who terrorizes people in their dreams. She is often depicted as a beautiful woman with long hair and has the power to suffocate or strangle her victims.

These are just a few examples of the many different types of evil spirits that exist in Russian folklore. It is worth noting that these creatures are not seen as embodiments of absolute evil in the same way that Satan is in Christianity - they are more like chaotic or mischievous forces that can be both good or bad depending on the situation.