Rule 34 Dev - abs anthro anus armpit_hair balls body_hair chest_tuft erection genitals humanoid_genitalia humanoid_penis looking_at_viewer male muscular muscular_anthro muscular_male nipples nude pecs penis simple_background solo tuft vein veiny_penis utx-shapeshifter mammal murid murine rat rodent 2021 black_and_white hi_res monochrome|20065899035