# Piercer
The piercer, p, is a monster class in NetHack that contains the following monsters: 

p rock piercer
p iron piercer
p glass piercer
Contents

1 Common traits
2 Description
3 History
4 Origin
5 Messages
6 Variants

6.1 Lethe patch
6.2 Convict patch
6.3 xNetHack
6.4 dNetHack

7 Encyclopedia entry
8 References

Common traits
Piercers are carnivorous animals that are always generated as hostile. They are capable of hiding on the ceiling, and attempt to fall onto you just as you pass beneath. The fall itself deals 4d6 damage regardless of piercer type, but is rather inaccurate and dependent on your AC - it has only a 3⁄5 chance to hit you at 10 AC, and will always miss a player with at least −2 AC. Wearing any metallic helm will reduce the attack's damage to 2 HP, with the blow glancing off it.[1] Finding a piercer via methods such as searching, warning or extrinsic telepathy will reveal them and prevent the falling attack from occurring.
Outside of this, piercers are the slowest monsters in the dungeon with a measly 1 speed - their sole bite attack is somewhat damaging for the point at which you first encounter them, but this can easily be mitigated by keeping your distance. Piercers have relatively low AC that can pose a problem to players lacking a decent weapon, but are otherwise trivial to dispatch.
All piercers leave ordinary fleshy corpses - the adjectives prefixing their names describe what each piercer resembles, rather than what they or their shells are composed of.

Description

Rock piercerIron piercerGlass piercer

p rock piercer 

Difficulty

4

Attacks

Bite 2d6

p rock piercer 

Difficulty

4

Attacks

Bite 2d6

Base level

3

Base experience

28

Speed

1

Base AC

3

Base MR

0

Alignment

0 (neutral)

Frequency (by normal means)

4 (Uncommon)

Genocidable

Yes

Weight

200

Nutritional value

200

Size

Small

Resistances

None

Resistances conveyed

None

A rock piercer:

 can cling to the ceiling.

 can blend in with its surroundings.

 cannot pick up items.
 has no eyes.

 has no limbs.

 is an animal.

 is carnivorous.

 is normally generated hostile.

Reference

monst.c#line661

Rock piercers are generally the first type of piercer you will encounter, and have a weaker AC of 3. It also gives less nutrition compared to the other piercers.

Generation
A rock piercer will always appear on the Plane of Earth.

p iron piercer 

Difficulty

6

Attacks

Bite 3d6

p iron piercer 

Difficulty

6

Attacks

Bite 3d6

Base level

5

Base experience

63

Speed

1

Base AC

0

Base MR

0

Alignment

0 (neutral)

Frequency (by normal means)

2 (Quite rare)

Genocidable

Yes

Weight

400

Nutritional value

300

Size

Medium

Resistances

None

Resistances conveyed

None

An iron piercer:

 can cling to the ceiling.

 can blend in with its surroundings.

 cannot pick up items.
 has no eyes.

 has no limbs.

 is an animal.

 is carnivorous.

 is normally generated hostile.

Reference

monst.c#line668

p glass piercer 

Difficulty

9

Attacks

Bite 4d6

p glass piercer 

Difficulty

9

Attacks

Bite 4d6

Base level

7

Base experience

106

Speed

1

Base AC

0

Base MR

0

Alignment

0 (neutral)

Frequency (by normal means)

1 (Very rare)

Genocidable

Yes

Weight

400

Nutritional value

300

Size

Medium

Resistances

Acid

Resistances conveyed

None

A glass piercer:

 can cling to the ceiling.

 can blend in with its surroundings.

 cannot pick up items.
 has no eyes.

 has no limbs.

 is an animal.

 is carnivorous.

 is normally generated hostile.

Reference

monst.c#line675

Glass piercers are acid resistant, and are the only piercers to possess any kind of resistance.

History
The piercer has been present in the game since Jay Fenlason's Hack - NetHack 3.0.0 introduces the three distinct types of piercer.

Origin
A piercer is a snail-like gastropod that first appeared in Dungeons &amp; Dragons. It has a shell that resembles a stalactite, and clings to the ceiling of caverns and dungeons, mimicking a stalactite and falling down to impale anything that passes underneath. The "bestiary of Xygag" mentioned in the encyclopedia entry is an in-universe equivalent to the Dungeons &amp; Dragons Monster Manual - the excerpt originates in "The Ecology of the Piercer" by Chris Elliott and Richard Edward, published in issue #72 of Dragon magazine.

Messages
A 

<foo> piercer suddenly drops off the ceiling!
A hostile piercer attempted to land on you.
You are almost hit by a falling <foo> piercer!
The piercer's falling attack missed.
You are hit by a falling <foo> piercer!
The piercer hit you and inflicted damage.
Its blow glances off your helm.
As above, but you are wearing a metallic helm, reducing the damage to 2.
Variants
Lethe patch
In the Lethe Gorge within the original Lethe patch, the second level contains an iron piercer along with another random p.

Convict patch
In the Convict patch as well as variants that incorporate the role, the lower filler levels on the Convict quest contain an assortment of piercers.

xNetHack
In xNetHack, piercers have a dexterity-based percentage chance to miss the player, and a speed-dependent chance to miss a targeted monster. A metallic helm will only halve the damage dealt from being hit by a falling piercer.

dNetHack
dNetHack adds the heaven piercer, which is much faster and stronger than most piercers - although still relatively slow - and can stun the player with its bite.
The Elder Sign is a ward that can repel piercers, as is the hallucinatory Cerulean Sign.

Encyclopedia entry

Ye Piercer doth look like unto a stalactyte, and hangeth
&nbsp;from the roofs of caves and caverns.  Unto the height of a
&nbsp;man, and thicker than a man's thigh do they grow, and in
&nbsp;groups do they hang.  If a creature doth pass beneath them,
&nbsp;they will by its heat and noise perceive it, and fall upon
&nbsp;it to kill and devour it, though in any other way they move
&nbsp;but exceeding slow.

the Bestiary of Xygag 

References

↑ src/hack.c in NetHack 3.6.6, line 2248

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