Wastri is a toadlike demigod who advocates human supremacy and the extermination of elves, dwarves, halflings, and gnomes. He is served by humanlike toads and toadlike humans. His realm is the Vast Swamp on the world of Oerth. He is lawful neutral with evil tendencies. In the recent past, he was imprisoned by Zagyg, but he has escaped.
Complete Divine, Dragon magazine #71
Living Greyhawk Gazetteer
World of Greyhawk boxed set