rule 34 3 toes 5 fingers anthro back muscles balls biceps black penis black tongue claws color swatch digitigrade dragon erection flaccid green eyes grey balls grey hair grey horn grey scales grey stripes grey tail hair horn humanoid penis long tail looking at viewer male male only model sheet multiple angles muscular muscular male neodokuro nude open mouth penis scales scalie sharp teeth simple background solo standing striped scales striped tail stripes tail tuft teeth textured background tharis toe claws toes tongue tuft uncut vein veiny penis 2193576