text: In the Marut Suktas (RV 1, 2, 5, 8) and Indra-Suktas (RV 1, 3, 8, 10) of the Rigveda (RV), the epithet "Rudras" – originating from the verb root rud or ru and meaning howlers, roarers or shouters – is used numerous times for the Maruts – identifying them with the Rudras even when associated with Indra, rather than Rudra. There are some hymns in the Rigveda (RV 2, 7, 8, 10) that explicitly distinguish between the Maruts and the Rudras.
  While the Vamana Purana describes Rudras as the sons of Kashyapa and Aditi, Maruts are described distinct from the Rudras as 49 sons of Diti, sister of Aditi and attendants of Indra.
  Ashwatthama
  Ashwatthama, the son of Drona, is the avatar of one of the eleven Rudras, along with being one of the eight Chiranjivi (the immortals). Drona performed many years of severe penances to please Lord Shiva in order to obtain a son who possessed the same valiance as the latter. Ashwatthama, the powerful son of Drona, though known as the part incarnate of Rudra, was really born of the four parts of Yama (death), Rudra (destruction), Kama (love) and Krodha (anger). Just before Mahabharata war, Bhishma himself declared that it would be virtually impossible for anyone to kill or defeat Ashwatthama in battle as he was the part incarnate of Rudra. Bhishma stated that when Ashwatthama becomes angry, it would become impossible to fight him as he would become "a second Shiva". The dishonoured death of Drona left Aswathama infuriated, and this event led directly to the annihilation of most of the Pandava lineage by the hands of Ashwatthama himself.