In UNDERTALE, Napstablook is a shy ghost who has a passion for music making. He is overwhelmingly insecure about himself and feels like a burden to you and everyone else. you can cheer him up so he feels better, and he will grow to like you. He is identical in OUTERTALE (other than the pretty stars that appear around him), in UNDERFELL, he’s a lot more spooky looking. his appearance looks like a torn unkept sheet. He is a lot more depressed and nihilistic. in a sad cry, he tells you how pointless life is, especially for a human living underground. he feels sorry for you as he knows what will happen next. Fell blooky's speech is also a lot slower than his UNDERTALE counterpart. in UNDERSWAP, his name is Napstaton, he was convinced by Undyne to inhabit a robot. She created which turned him into a famous DJ and radio star. since he trades places with Mettaton from UNDERTALE, he is way more confident in his ability to make music, and he also is a little egotistical. Of course, he still has his "blooky" moments where if something goes wrong, he may burst into tears. (for some reason, Undyne allowed that to be built onto his robot form.)