Shade

Shade
Difficulty	14
Attacks	Paralysis 2d6, speed drain 1d6

Shade
Difficulty	14
Attacks	Paralysis 2d6, speed drain 1d6
Base level	12
Base experience	357
Speed	10
Base AC	10
Base MR	0
Alignment	0 (neutral)
Frequency (by normal means)	No random generation
Genocidable	No
Weight	1450
Nutritional value	0 (and no corpse)
Size	Medium
Resistances	Cold, Sleep, Disintegration, Poison, Petrification
Resistances conveyed	None

A shade is an undead creature, created by black magic.

It cannot be harmed except with blessed or silver objects, magic, or artifact weapons with a damage bonus. Orcus Town is the only place where shades appear. If you've got this far without an alternative, you can use the Bell of Opening as a silver weapon against them. Unarmed gloveless combat with a silver ring equipped can also work, as can unarmed combat with blessed gloves (although this is very slow.)

Shades can also move freely through solid rock, and can see invisible creatures.

Encyclopedia entry

Shades are undead creatures.  They differ from zombies in
that a zombie is an undead animation of a corpse, while a
shade is an undead creature magically created by the use
of black magic.