Derived undead

In Crawl, there are four forms of undead monsters that are derived from a base monster. Instead of having set properties, theirs are modified from that of the monster that they originally were. There are four types: zombies, skeletons, simulacra, and spectral things.

While abominations are created from the corpses of dead monsters, their stats are not related to those of the original monsters used in their construction, although they are related to the total HD of corpses used to assemble them.

Common properties

All derived undead have 2 less speed than their original, to a minimum of 3. Notably, this means that normal speed monsters will have derived forms that are considerably slower than the average player. In addition, all derived undead monsters have the same HD as their original form. Lastly, derived undead monsters lose all special attack properties other than constriction, and lose all resistances and vulnerabilities that their original form had, although they gain undead resistances.

Derived undead have their attack damage slightly decreased. Each attack is reduced by 20%, to a maximum reduction of four (per attack). Thus, an undead quicksilver dragon, whose base form does 25 and 20 damage, will have a 21 damage attack and a 16 damage attack.

All derived undead have undead resistances and vulnerabilities: immunity to poison, rot, negative energy, drowning, and torment, and vulnerability to holy effects. They all also gain cold resistance, but to differing degrees (see below).

A few other properties will also be retained by undead monsters, if their base form had it:

• The ability to trample.
• The ability to fly or levitate, even for skeletons of winged monsters and other things which arguably shouldn't be able to fly.
• The monster's natural habitat. Big fish zombies will not suddenly learn how to walk on land, but alligator snapping turtle zombies will not suddenly forget how to swim.

All other properties, including any spells or innate abilities, will be lost. Also, the monster's undead base monster will be its genus base monster: thus, a orc high priest will simply become an orc zombie. What is a genus is not always obvious: all elves are the same genus, whereas each giant type has its own, separate genus.

Zombies

The most basic form of derived undead, zombies are almost invariably sturdier than their base monster, but also generally much stupider.

• HP: HDd5 + 6*HD
• AC: Original - 2
• EV: Original - 5
• Cold resistance: rC++
• Attack flavour: plain
• Intelligence: Zombie (in general, means they don't care about walking into traps/dangerous clouds)
• Special: Cannot use stairs, lose HP from max HP (means they cannot regenerate, but also makes it impossible to tell how injured they are)

Zombies and skeletons cannot normally use items, but they will continue to use any items the original monster had, provided such items have not been picked up before the zombie/skeleton is raised.

Skeletons

Skeletons are similar to zombies, but have worse HP, AC, and EV. The benefit to creating skeletons if you are a necromancer is that you can eat the flesh of the original monster. Note that some monsters can be made into zombies, but not skeletons (most notably insects).

• HP: HDd4 + 5*HD
• AC: Original - 6
• EV: Original - 7
• Cold resistance: rC++
• Attack flavour: plain
• Intelligence: Zombie
• Special: Cannot use stairs, lose HP from max HP

Simulacra

Simulacra are the weakest undead in terms of HP, but those with high HD can have massive damage output from their cold attacks.

• HP: HDd4 + 1*HD
• AC: Original - 2
• EV: Original - 5
• Cold resistance: rC+++
• Attack flavour: Cold (do an extra HD to 3*HD - 1 cold damage per attack)
• Intelligence: Zombie
• Special: Cannot use stairs, vulnerable to fire, lose HP from max HP, player-created simulacra are temporary, when killed leave behind a 1-square freezing cloud

Spectral things

Spectral things are the only derived undead to not have the intelligence of a plant. They have less HP than skeletons and zombies, but in general make up for this by having better intelligence and the ability to use stairs. They also have better AC than their original form.

• HP: HDd4 + 4*HD
• AC: Original + 2
• EV: Original - 5
• Cold resistance: rC+
• Attack flavour: Up to two attacks will have the draining flavour, similar to that of wraiths.
• Intelligence: Normal
• Special: Can use stairs, can levitate, regenerate normally and lose HP normally, can see invisible, spectral things from Death Channel are temporary, but those created by Yredelemnul's invocation are not.

Yredelemnul's Enslave Soul invocation will create a special spectral thing for you: this will be normal speed, have the same spells as the original monster, and be permanent.