Non-magical saving throws? (Especially INT, WIS, and CHA)

[Greywander]

There's a couple races that give advantage to saving throws under certain conditions.

Gnomes, the classic PHB race, have advantage on INT, WIS, and CHA saving throws against magic.
Yuan-ti purebloods, a race from Volo's, have advantage on all saving throws against magic.
Vedalken, from Ravnica, have advantage on all INT, WIS, and CHA saves. Magic or not.

Clearly, either of the other two races are an upgrade from the gnome, at least in terms of saving throws, but I'm trying to figure out which one is better. What it seems to come down to is how common non-magic saving throws end up being. And the only things I can think of off the top of my head are DEX saves for dodging traps, CON saves against poison, and DEX/CON saves against dragon breath. Neither of these races would have advantage on such saves.

There's enough spells that use DEX or CON saves that the yuan-ti seems like the clear superior choice, so I guess the real question is, how common are INT, WIS, or CHA saves that are non-magical? Are there any?

[Malifice]

Fear/ frightened/ frightful presence is a super common Wisdom save that isn't due to magic.

Just down to the thing being scary.

[Greywander]

D'oh, how did I forget that? I even remembered dragon breath, yet forgot Frightful Presence, which is also found on just about every dragon.

[LudicSavant]

how common are INT, WIS, or CHA saves that are non-magical? Are there any?

There are quite a lot. Note that "magic" is a narrower category that one might assume (http://dnd.wizards.com/articles/features/rules-answers-february-2016) (e.g. just because something's supernatural doesn't make it count as "magic").

There are a bloody ton of INT/WIS/CHA saves that are non-magical according to this definition. Fear is an especially common one. There's also stuff like the Battlemaster's Goading Attack or a Gibbering Mouther's Gibbering or a Mind Flayer's tentacles.

[Vogie]

The optional Sanity section in the end of the DMG gives a way to use either Wisdom or Intelligence in a way to have your characters react to both magical and non-magical mend-bending-ness

IIRC, fending off Ghostly possession uses a Charisma Saving throw

Mind Flayers cause a Int Saving throw when grappling a target to attempt to also paralyze them

Phantasmal force (the spell) requires an Intelligence Saving throws to believe or disbelieve an illusion - you could expand that model to all types of illusions, including mirages or Shadows (the 3.P mechanic)