rule 34 2016 anal anal sex anatomically correct anatomically correct penis animal genitalia animal penis anus ass backsack ball stretcher ball tugging balls ballsack black anus black balls black fur black mane black penis black tail bondage bound bridle buttplug cock ring cum cum on ground cum while penetrated cumshot digital media artwork ejaculation equine equine penis erection feral flared penis fur gradient background grey hooves hi res hooves cock male male only mammal mane multicolored fur multicolored penis open mouth orgasm penetration penis perineum pink penis quadruped raised tail rear view reins rufciu scrotum sex toy shadow signature simple background snout solo spreader bar tail wraps tan fur teeth testicle cuff testicles two tone fur two tone penis vein veiny penis wraps yellow eyes 2430753