rule 34 2015 anthro anus ass blue arms day duo echidna fur furry ears furry tail green eyes hedgehog hi res interspecies knuckles the echidna looking at viewer looking back male male only male pov mammal monotreme multiple males nude open eyes open mouth outdoors pointy ears pov raised tail smile solo focus sonic series sonic the hedgehog spice5400 tail testicles yaoi 1783020