Rule 34 Dev - 1boy 2023 animal_genitalia animated anthro anthro_to_feral balls balls_expansion becoming_erect big_balls big_penis big_sheath blue_body blue_fur body_size_growth breath canid canine canine_genitalia erection expansion feral fur genital_expansion genitals getting_erect gif hybrid keavemind knot looking_at_viewer male male_only mammal moon mustelid otter panting penis penis_expansion pink_penis sheath signature simple_background size_transformation solo tail teeth throbbing throbbing_penis tongue tongue_out transformation were werecanid werecanine weremustelid wereotter werewolf|10574991008