FURVERT!

against_natural_surface against_surface against_tree anal anal_penetration anthro anthro_on_anthro anthro_penetrated anthro_penetrating anthro_penetrating_anthro balls biped bowser butt canid canine collar cutaway duo erection from_behind_position genitals hi_res horn humanoid_genitalia humanoid_penis internal interspecies koopa leash male male/male male_penetrated male_penetrating male_penetrating_male mammal mario_bros mkcrown nintendo overweight overweight_male penetration penis plant scalie sex shell spiked_shell spikes spikes_(anatomy)tree vein veiny_penis