How did Ravan got his name and his 10 heads
Ravana the greatest Shiva bhakt, though he is villain in Ramayana he has few great qualities which made him Ravan the extraordinary. he was the greatest villain of Sri Maha Vishnu avataras.
Ravana was a staunch follower of Lord Shiva, Excellent Ruler, Maestro in Veena, Learned whole 4 Vedas, has many skills in various Arts. Ravana was such a great devotee of Shiva that once he gave unbelievable sacrifise to please him on the banks of river Narmada. The story says Ravana had axed his head to please Lord Shiva, Each time that happened, the head grew back, which continued 10 times, pleasing Shiva. Shiva thus granted 10 heads to Ravan that he sacrificed. These 10 heads indicate the six shastras and the four vedas that Ravan mastered.
After winning over Lanka, Ravan again went to meet Shiva in Kailash, where he was denied entry by Nandi-Shiva’s gatekeeper. Annoyed, Ravan teased him and hence a furious Nandi cursed him that his Lanka would be destroyed by a monkey! To prove his devotedness to Shiva, Ravan tried to lift Kailash. Angry Shiva placed a toe on the hill and Ravan’s hand crushed beneath it, so painfully that his cry shook the world.
To please Shiva now, Ravan plucked out his nerves and played Shiva’s praise to which Shiva released him and gifted him a sword and gave him the name Ravan, which means “the one with terrifying roar”.