rule 34 animal genitalia animal penis anus ass balls blue body blue eyes blue fur claws countershade torso countershading dart frstr4706 digital media artwork dragon erection feral fur furred dragon genitals hi res horn knot looking at viewer looking back lunalei male membrane anatomy membranous wings penis presenting presenting balls presenting hindquarters presenting penis raised tail rear view ridged penis simple background solo striped body striped fur stripes white body white fur wings 4515203