It's probably because I have no skill in relating or reading people's emotions, but many of these eyes don't exactly look like they're displaying the emotions they're supposed to...
It is the lack of eyebrows that make them so random, too.
Cat EyesTomodachi / FriendWomanCryingManYandereLaughingSidelong GlanceSurprisedAngryTaremeTsurimeLet's try drawing various eyes!Compound EyesImage TrainingUsual generic eyes
General purpose, multi-purpose etcYoshi
「でっていう」 (Detteiu) stems from the sound effect Yoshi makes when mounted by Mario in Super Mario World. It is what people thought it sounded like, and has since become both a second name for Yoshi, and a popular pet-name.