Sans The Skeleton, everyone! I tried to make it as detailed as possible, mentioning his and Papyrus' personality and appearances, and even someone else..heheh. I do hope you enjoy!

This is Glitchtale Gaster from Origins! Another version, heheh. I'd say it is very accurate, though the setting is during the war. Gaster has been captured by the humans.

This is Swapfell Sans! Or, well, Nox. This skeleton is hard to impress and has an extremely high view of himself...though is prone to believing rumours such as ladder ghosts. The image used is from Bonely Hearts Club!

This is Dr. W.D. Gaster, before the war between humans and monsters began. The 'Great' War. Back then he was part of the wizard council, and he had a family.