FURVERT!

2023 3:2 animal_genitalia animal_penis animated animated_gif 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 canine_penis canis castor_(shiningcastor)detached_sheath erection expansion feral feral_transformation fully_sheathed fur genital_expansion genitals growth hybrid keavemind knot knot_in_sheath looking_at_viewer male mammal moon mustelid mythological_canine mythological_creature mythology otter panting penis penis_expansion penis_tip pink_penis sheath short_playtime signature simple_background size_transformation solo tail teeth throbbing throbbing_penis tongue tongue_out transformation urethra werecanid werecanine werecreature weremustelid wereotter werewolf wolf y_sheath_opening