Piercing damage
I think that there should be more piercing damage. Claws and teeth -- meaning most creatures -- should be piercing instead of normal.
I'm assuming they are normal because when I'm hit and take damage, I'm seeing the red rectangle off the health bar, and red seems to mean normal damage.
Spikes are piercing damage!

As far as I know, larger red lichen, sloom and toxigels' spin attack are piercing as well as the pitchfork attack from Overtimers and Firebranders. Those are the only piercing attacks I'm aware of, (if you don't include spikes and thickets).
I agree with making claws/teeth piercing damage. Because it should be standardized that anything pointy is piercing to lessen confusion on players. Even though teeth and claws may not pierce deep into you, they're still sharp and pointy.
i disagre with making claws piercing, as stated before, because it's more like a slash attack than a ierce attack...unless the attack itself is in a thrust motion, impaling into the target...so, only at this kind of attack it should be considered piercing. About teeth, i agrre in making then piercing, as they look more like this than slash, anyway.
- Because it should be standardized that anything pointy is piercing to lessen confusion on players.
- - kojiden
Sounds like you'd just like them to change normal to blunt damage, and piercing to sharp damage.

They should make Chromalisk tongues piercing damage since they can go through solid walls.
i swear i read somewhere that 'piercing' attacks were ones designed to penetrate armor
since a lot of player equipment seems to have quite decent piercing defense i assume this is meant to mean, piercing attacks used by a player will tend to ignore monster defenses
that said, it seems like the separation of damage types AT ALL is a gimmick that allows the player to
1) observe the levels in a gate and predict the type of enemies they will encounter (haunted passage = zombies )
2) use previous experience to determine what types of attacks those enemies use (zombies = shadow damage, weak vs elemental)
3) use this foresight to modify their equipment loadout for optimal adventuring in their intended stomping ground (high shadow defense armor and an alchemer)
4) ????
5) PROFIT
if more enemies were known to use piercing-type attacks (however you rationalize it) then players could use this knowledge to prepare for dungeons even better
this is probably a good thing

Originally I thought the four damage types were two opposites.
You know, something strong against Piercing Damage would be weak to Normal, something strong against Shadow Damage would be weak to Elemental.
So in a pickle people would always be able to figure out what weapon to use.
But then I noticed stuff, like the player armour.
There was Plate Mail sitting there with massive resistances to Normal and Piercing attacks.
And the Magic Cloak with massive Elemental and Shadow resistances.
The types don't seem to make any sense whatsoever, they're just randomly plopped about.
Which begs the question:
Why bother having multiple damage types if they're all treated like the same damage?
If all damage types aren't equal, why bother with them at all?
It makes no sense to me.
It's kind of like, each type of monster has a different attack type. When you gear up, you can choose to gear up according to what you think are the most prevalent damage types.
Think of plate mail like platemail + chain mail, which in real life, deflects slashing attacks with the plate, and piercing attacks with the chain links underneath.
Magic Cloak is strong against "magic stuff" like Shadow and Elemental, but weaker against physical stuff.

the most prevalent damage type
You see, to me that means there's a design flaw.
You have four types of damage, but people still have only one choice in defensive equipment.
There shouldn't be a prevalent type at all. People should be able to choose to go in with what they think they need protection from the most and expect to find monsters that deal that damage type.
Not just go get the highest Normal Resistant armour in the game with stacks of Fire Bonuses and become He-Man.
Players should be able to choose any type of resistance and still do as well as anybody else in a dungeon.
Otherwise you end up with Pokemon, where everything weak to Rock and Ground is a No-Go.
It seems like a waste of having the other damage types there if there's always going to be one prevalent type of damage, at any stage of the game.
- You see, to me that means there's a design flaw.
- - Shoebox
I think everyone agrees with you on that point, including the devs. It sounds like they're still working on it.
Yeah, when it shows red bars falling from you it's normal damage. I don't really think claws would be piercing, as they're only being raked across you. Teeth is probably debatable, as they are being sort of sticking you in a way, but it seems like they'd be too short to actually pierce anything.