Thanatos was the masked leader of the gang of terrorists known as the "Death's Head", devoted to the destruction of capitalism. Using a strange device invented by Amos Fortune, the so-called "Fortu-Tron", they manipulated several millionaires (including Bruce Wayne) to lose their judgement and gamble away their money. The Death's Head were defeated by the Batman, and Thanatos was unmasked as a Sophia Santos, a.k.a. "Lina Muller", a reporter who had associated with the Batman.
Thanatos II Has Not Appeared In Any Other Form Of Batman Media