Sphere
Spheres, e, are a class of monster in Nethack. This class is made up of monsters that act like "living mines", always exploding upon death. They will self-destruct and harm you; they also blow on you if you kill them in melee. Dextrous players can sometimes dodge the explosions completely, while players with the correct resistance might not feel harm from the blast (though their inventory might still take damage).
Monsters in this class:
Gas spores e are different to spheres in that they will never attack you and explode only if attacked. However, gas spores explode in a 3-by-3 square, thus even if a character survives the blast, a nearby pet might die. Peaceful creatures caught in the blast also become hostile.
Black lights and yellow lights, y, are not spheres, but they self-destruct in a similar manner.
In Slash'EM, flame and freezing spheres can be summoned by the fire and ice mages respectively. Although low-level characters may find their use frequent and helpful, monsters killed by the explosions do not contribute XP to the player, which makes them a missed blessing. They are, of course, useless if the opposing monsters resist fire or cold. Too much use can also cause swift extinction of the species.
