why does his laughing sprites look so sad ):

I don't really like how these sprites were put in onto this sheet, as the sprite where the mouth appears to be open is the "first" sprite.

@JUGOSILLOSO Actually, you're thinking of the dating sequence. In those, Papyrus's mouth is a 3-frame animation.

As for everyone else mentioning the battle sprites being different, this is indeed the case, although it's a rare occurrence in the game- Sans, Papyrus, and Alphys are the only characters whose talking sprites are significantly different from their battle sprites. Everyone else's talking sprites are either identical or edited versions of their battle sprites. Toriel, Mettaton, Asgore, and Asriel's are cropped versions of their battle sprites, and Undyne's a bit of a weird case where her head is directly cropped from her battle sprite, but her ponytail is different.

I APPROVE.

@TheMorningFlash15: No it's not.

@gerpity They're unused.

where does the cool dialogue face appear?

@Fillerthefreak: Actually, if you pay close attention, Sans' eyes are more "opened" in his dialogue expression than in his battle/ending sprites. I always wondered why they seemed different and it took me a while to realize that was it.

There's only two sprites for each in the game's data, so there's nothing missing here.

Hmm, I think the "talking cycle" is 3 sprites instead of 2 for every mood... Not sure at all >.

@NathurTheVGPlayer: Fixed, and added an animation that was missing.

I just noticed that the 2nd frame in his Mad sprite is wrong

I always never understood why these sprites are more blocky than the in-battle faces.

If I'm correct, Sans' battle sprite face his is text box icons. Never understood why the same thing with Papyrus.