An egg is a comestible in NetHack which may also hatch into a monster if left uneaten. If an egg hatches, the hatched monster may become your pet. For the purpose of conducts, eggs count as vegetarian but not vegan.
One in three generated eggs is from a non-unique, non-aquatic and oviparous species, picked according to the normal random monster generation for the current level. The species of monster eggs can be identified by any magical method; monster eggs can also be identified by seeing one hatch. If the post-identification type is still just "egg", it is not a monster egg (presumably just an ordinary unfertilized hen egg); if it is a monster egg, you will be able to recognize the type in the future.
Polymorphing into the adult form of an oviparous monster (regardless of gender) will also identify all future eggs of that type; polymorphing into any type of adult dragon will identify all types of dragon eggs as well.
Eggs provide 80 nutrition when eaten, but don't provide any intrinsics that the corresponding corpse would provide. An egg becomes stale after 400 turns; the spell or wand of undead turning can rejuvenate stale eggs. A stale egg makes you nauseated for 10d4 (more) turns, eventually causing you to vomit unless cured.
If the egg is a cockatrice egg, you will suffer delayed petrification unless resistant. Unless you identified the egg, you will not know whether it's a cockatrice egg until you eat it. Pets which aren't petrification-resistant will avoid eating cockatrice eggs, which is one way to informally identify them.
If you polymorph into a female oviparous monster, you can lay an egg with the #sit command, and when it hatches it will become your pet. Laying an egg will reduce your nutrition by 80. Breaking your own eggs carries a -1 Luck penalty each, to a maximum of -5 for a single stack; eating them does not, but grants no net nutrition gain. A randomly generated dragon egg will also become your pet if you are carrying it when it hatches. If you are male, there is a 50% chance that any egg which hatches while you are carrying it will become your pet.
Eggs will only hatch if in your inventory or on the floor; if kept in a container on the turn it's supposed to hatch, the egg will turn infertile. Zapping an egg with a spell or wand of undead turning will re-fertilize it and reset the hatch timeout. Strangely enough, re-fertilizing eggs will not affect their age (so they may still be stale or rotten).
Eggs kept in an ice box will not age and become rotten; however, this does not suspend their hatching timer, so leaving an egg in an ice box for too long will prevent it from ever hatching.
The following information pertains to an upcoming version (3.7.0). If this version is now released, please verify that it is still accurate, then update the page to incorporate this information.You can apply royal jelly to an egg to revive it and potentially make it see you as its parent.
Although eggs have a surprisingly high nutrition/weight ratio, eating them can be dangerous due to the stunning. They may be rotten and cause you to vomit, or they may be cockatrice eggs, which will cause delayed stoning if you eat them. If you are already satiated, you won't get a warning about eating an egg, even if it would choke you to death. It is often safer to leave eggs sitting on the ground as food for carnivorous pets.
You can wield an entire stack of eggs, which will cause them all to break in a single attack; you can use #adjust to avoid this. If you break a stack of your own eggs, the Luck penalty is −1 for each egg, up to a maximum of −5. They can also be thrown as weapons, though they will break 99% of the time.
Cockatrice eggs are popular as projectiles that will petrify any stoning-susceptible monsters they hit. (When used this way, they are sometimes referred to as "grenades".) When you throw an egg, there is a risk that it will miss its target and go to waste, so you may prefer to wield the egg — unlike wielding a cockatrice corpse, this does not have the risk of petrifying yourself. Naturally, using cockatrice eggs that you have laid yourself incurs the aforementioned Luck penalty.
- Ugh. Rotten egg.
- You ate a egg that sat around for too long and became rotten; you are now nauseous.
- You see a <monster> drop out of your pack!
- An egg hatched while you were carrying it.
- Its cries sound like "<mommy/daddy>".
- A newly hatched monster came out tame and is now your pet.
But I asked why not keep it and let the hen sit on it till it
hatched, and then we could see what would come out of it.
"Nothing good, I'm certain of that," Mom said. "It would
probably be something horrible. But just remember, if it's a
crocodile or a dragon or something like that, I won't have it
in my house for one minute."
- mkobj.c in NetHack 3.6.1, line 870
- mon.c in NetHack 3.4.3, line 2596
- eat.c in NetHack 3.6.0, line 1775
- eat.c in NetHack 3.6.0, line 2112
- eat.c in NetHack 3.6.0, line 1714
- sit.c in NetHack 3.4.3, line 303
- dothrow.c in NetHack 3.4.3, line 1588
- timeout.c in NetHack 3.4.3, line 432: The identity of one's father is learned, not innate
- src/timeout.c in NetHack 3.6.2, line 740: the chance not to hatch is 150^50 * 150! / 200! ~= 0.00046
- dead_species in mon.c
- obj.h in NetHack 3.4.3, line 207
- timeout.c in NetHack 3.4.3, line 389
- revive_egg in zap.c
- uhitm.c in NetHack 3.4.3, line 757
- breaktest in Dothrow.c
- dothrow.c in NetHack 3.4.3, line 1588