Notes:

Created with https://tiermaker.com/categories/super-smash-bros-ultimate/super-smash-bros-ultimate-tier-list-now-with-extras

Special cases:
- Mii Fighters: custom hairstyles ranking from bald to waist-length. The Viridi wig is longer than a Mii's body height.
- Bayonetta: her bodysuit is made of her own, magically manipulated, extremely long hair.
- Inklings: they have tentacles, not hair. They would be in the Classic tier otherwise.

Fixes:
- Megaman (thank you @kirbman), Morton (thank you @MIZZO_No_004). Both were incorrectly placed in the "None" category.
- Bowser, Bowser Jr., some Koopalings (thank you @simito97). They have hair and scales indeed.
- Sephiroth and Palutena now in separate tiers (thank you @Kommando_Kaijin)

Tier labels mean "at least ###-length hair". Classic hair length is slightly longer than hip-length.

I assume that Mewtwo's skin is covered by fine cat-like fur, though others say that Mewtwo is bald. I'm also assuming that Min-Min has hair that looks like ramen noodles instead of actual noodles for hair. I'm not sure about the Minecraft characters.