21542892525

artist

doomboy84

character

alphys

gaster

invalid

lore

copyright

undertale

undertale

species

humanoid

lizard

reptile

scalie

meta

digital media

digital painting

english text

translated

general

anthro

bone

dark

duo

female

laboratory

male

male/female

ominous

railing

scientist

skeleton

text

1boy 1girl 2020s 2023 2d 2d_(artwork) animated_skeleton artist_name artist_watermark blue_breasts blue_nipples blue_tongue bottom_sans breasts clothed clothed_male clothing cum cum_on_face digital_media_(artwork) duo ech7474 ectopenis female_sans gaster gaster_(undertale) genderswap genderswap_(mtf) genitals gloves hooded_jacket hoodie jacket licking licking_face licking_penis male male/female monster multiple_views nipples nude off_shoulder orange_penis paizuri penis purple_background rule_63 sans sans_(undertale) sanster seme_gaster sex simple_background skeleton solid_color_background sweater tears top_gaster twitter uke_sans undead undertale undertale_(series) video_game_character video_games watermark white_gloves

2010s 2016 2boys 2d 2d_(artwork) animated_skeleton arms_behind_back artist_name beoteono black_tentacles blue_blush blue_penis blush bodily_fluids bottom_sans buttercupsticks clothed clothing cussing dominant dominant_male drooling duo ectopenis feet_out_of_frame fluids gaster gaster_(undertale) grabbing_another's_chin grabbing_chin grey_background hand_under_chin hands_behind_back male male/male male_focus male_only maledom malesub monster one_eye_closed partially_colored penis precum profanity sans sans_(undertale) sanster seme_gaster simple_background skeleton soul soul_sex submissive submissive_male swearing tentacle tentacle_on_male tentacles tentacles_around_legs tentacles_on_male text top_gaster uke_sans undead undertale undertale_(series) video_games yaoi