The word Rakshasa is in Sanskrit, Raksasa is for male while Raksasi is for female. According to the Hindu mythology, Rakshasa in general is a type of demon or goblin. They have the power to transform into animals, or monsters, or in the case of the female demons, as beautiful women.

They become most powerful during the dark hours of the night but are weaken by the rays of the shining sun. Like most other evil beings, they hate prayers and sacrifices.

The most powerful among the Rakshasa is their king, the 10-headed Ravana. It is said that Ravana was killed by the Goddess of Destruction, Kali. Another demon, the female Putana, is also well known for she tried to kill baby Krishna by offering him milk from her poisoned breasts. She was however killed by the Gods.

[ Young Krishna ]
Although not all Rakshasas are equally evil, since some of them are actually the Yaksas (nature spirits) while others are similar to Ashuras (opponents of the Gods), the term Rakshasas generally applies to demons who haunt cemetaries, drink cow blood and eat the human flesh.

Sculptures and paintings show them with horrible appearance, sharp side tusks, ugly eyes, weird eyebrows, and carrying brutal weapons.
[Posted at: Rakshasas]