Rule 34 Dev - anthro anus ass balls canid canine fox ftm_crossgender genderswap_(ftm) genitals hair heart krystal looking_at_viewer looking_back looking_back_at_viewer male male_krystal male_only mammal monochrome nintendo nipples nirvana3 nude penis perineum presenting presenting_anus presenting_hindquarters rule_63 signature smile solo star_fox|9941958320