Also the Classic Maya god of rulership and thunder known to modern Mayanists as `` God K '' , or the `` Manikin Scepter '' and to the classic Maya as K ` awil was shown with a smoking obsidian knife in his forehead and one leg replaced with a snake . Also the Classic Maya god of rulership and thunder known to modern Mayanists as `` God K '' , or the `` Manikin Scepter '' and to the classic Maya as K ` awil was depicted with a smoking obsidian knife in his forehead and one leg replaced with a snake .