Some of my favorite artists are Novasiri, Geelly, and Nyascree. idk if they're underrated but I think giving them some extra attention won't be a bad idea uwu
Novasiri is the creator of a fantasy webcomic named Aether Eternius. I love their character designs, they're amazing and fit well within their cartoony art style.
Geelly is mostly a Warrior Cats fan artist from what I know/see, and has a beautiful, unique art style.
Nyascree is an adoptable maker and digital artist (and also on TH under the same name if you wanna check 'em out) who draws a lot of monster people and creatures and has a great art style.