1boy 1girl androgynous bad_id bad_pixiv_id blue_skin blue_theme book closed_eyes eyepatch fang frisk_(undertale) g_perarikku gerson hat head_fins magnifying_glass monochrome monster_girl mushroom one_eye_closed open_mouth petting ponytail sharp_teeth shirt short_hair short_sleeves smile teeth thick_eyebrows turtle undertale undyne