Rule 34 Dev - 2008 abs anthro balls black_and_white bruno_rhynox concept_art erection flaccid genitals hi_res humanoid_genitalia humanoid_penis male mammal masturbation monochrome muscular muscular_anthro muscular_male nipples pecs penile penile_masturbation penis plantigrade pubes rhinoceros solo tattoo tomcat_(artist) vein veiny_penis|9990836280