FURVERT!

2d_animation accident accidental_exposure animated animated_gif anus backsack balls balls_expansion big_balls big_butt bursting_out bursting_out_of_clothing butt butt_expansion clenched_teeth clothing dock_(anatomy)equid equine expansion fasttrack37d feral frame_by_frame genital_expansion genitals growth horse male mammal nude open_mouth puffy_anus short_playtime solo species_transformation tail tail_growth teeth throbbing throbbing_balls torn_clothing transformation wardrobe_malfunction