Lycanthropy is an intrinsic conveyed by being bitten by a werecreature – a werejackal, wererat, or werewolf. It is also conveyed by eating the corpse of one of the above (if you are human, this is considered cannibalism). The message "You feel feverish" is displayed upon acquiring the intrinsic from a bite.
The intrinsic transforms you into the animal form at regular intervals. Quaffing a potion of unholy water will do the same. While in were form, you can summon jackals, rats, or wolves as pets. Polymorphing will toggle between forms.
Lycanthropy is generally considered intrusive as animal forms tend to get encumbered by inventory that was no problem before. Werewolves, in addition, will destroy their shirt, cloak, and body armor when transforming to animal form. To remove lycanthrophy, you can pray to your god (it counts as a major problem – if successful, "You feel purified."), eat a sprig of wolfsbane, or quaff a potion of holy water. If none of these options are available, an amulet of unchanging or ring of polymorph control will keep the intrusive changes under control. Otherwise, you can at least force yourself to transform back into human form by letting yourself get hit by anything that damages (e.g. a monster). When your hp reaches zero, you'll transform back to normal, with the hp you have as a humanoid.
A user has suggested improving this page or section as follows:
"The player receives silver damage and cannot handle silver items while afflicted by lycanthropy, even in human form - "You can't handle your xyz!""
Summoning fellow monsters
While in a changed form, you can use #monster command to call for help – summoning a few monsters of the same species as yours. The fellow monsters summoned by using the #monster command will remain tame after you have returned to human form, or if you become cured, effectively becoming your pets.
A very large number of pet jackals, rats, or wolves can be acquired by summoning help over the course of several transformations to the were form. These pets will be very weak, but you can polymorph them into an army of unstoppable monsters (or use them as temporary meatshields).
One thing to note is that calling for help with #monster requires some power – the same kind that the character uses for spellcasting – and if you don't have enough power, you get a "You lack the energy to send forth a call for help!" message and cannot summon any monsters. This can pose a bit of a problem for very low level characters.
Lycanthropy can be beneficial as it confers drain resistance while in animal form, and you have the option of summoning many tame pets. If you wear an amulet of unchanging, or have polymorph control (from wearing or eating a ring of polymorph control or in SLASH'EM choosing the doppelganger race and reaching level 9) you may choose not to transform into your were form (providing you are conscious and in good health), leaving no adverse effects.
Lycanthrope is a starting race in SLASH'EM in which you start with Lycanthropy, though you are automatically a werewolf, and cannot choose to be a were-anything else if that is your starting race. However, unlike characters that have been bitten by a werewolf, natural Lycanthropes will remove their armor before transforming, rather than destroy it (unless it is cursed).
- In general use, the word "lycanthrope" (from ancient Greek λύκος (lýkos, "wolf"), άνθρωπος (ánthropos, "man")) simply means "werewolf", but in D&D, which NetHack heavily borrows from, the term is extended to apply to all shape-shifting were-creatures.
- pray.c in NetHack 3.4.3, line 169
- eat.c in NetHack 3.4.3, line 1681
- potion.c in NetHack 3.4.3, line 467: Code path for chaotics
- potion.c in NetHack 3.4.3, line 483: Code path for nonchaotics