Rule 34 Dev - abs absurd_res avian martlet_(undertale_yellow) undertale anthro avian_arms avian_feet beak biceps big_breasts big_muscles biped bird black_body black_feathers blue_beak blue_body blue_feathers blue_hair breasts butt censored digital_media_(artwork) feathers feet female fingers full-length_portrait genitals hair hi_res ineffective_censorship long_hair looking_at_viewer martlet_(zenith_form) muscular muscular_anthro muscular_female neck_tuft nipples nude pecs portrait pose pussy simple_background smile solo standing tail tail_feathers talons thick_thighs toes tuft undertale_(series) undertale_yellow unknown_artist yellow_eyes|12426893568