Ravana had ten heads and therefore he is also called Dashanana. But did he really have those fabled ten heads?
There are many versions of this myth. Some say that Ravana was actually a scholar of ten sacred texts and thesis : six Darshana (Sankhya, Yoga, Nyaya, Vaisheshika, Meemansa, Vedanta) and four Vedas (Rig, Yajur, Sama, Atharva). For this he was metaphorically called “Dashkanthi”, which means one who can speak from ten throats. In time, he came to be known as having ten heads.
If Jain scriptures are to be believed, then Ravana would wear nine Mani (crystal balls) in his neck that would reflect his head and create an illusion of having ten heads. Many Purnaic scholars believe that Ravana was Mayawi (charlatan) having knowledge of mysterious tricks and he could easily have created illusions about himself. The legend of Marich is noteworthy here. Marich was an illusionary golden antelope created by Ravana through Indrajaal (illusionary powers) to lure Sita away and capture her.
Ramacharitmanasa, written by Goswami Tulsidas, describes Ravana as one with ten heads and twenty arms. He had gone to fight on Amawasya (no moon’s night) and every single day he would lose his one head in battle. Thus, on the tenth day, i.e. on Dashami of Shukla Paksha, he was finally killed. This is the day when Dussera is celebrated as the festival of victory. Ravana effigy with ten heads are set on fire symbolically to mark the Vijay Parv.