Vampire moss hangs from trees and branches in marshy or tropical environments, waiting for other creatures to wander past it so that it can feed upon them.

This plant is normally pale green in color, and it grows to a length of 1 to 4 feet. The moss grows in a netlike mass, but it is not as thick as that which grows upon rocks.

Combat: Vampire moss lives upon the life energy of other creatures, but it prefers mammals – especially intelligent ones, possibly because their living essence tends to be more vibrant. The moss is an “air feeder”, meaning it requires no contact with other creatures in order to draw life energy from them. A victim need only pass within 10 yards of the moss in order to be “attacked”.

When vampire moss attempts to feed on a person, he feels a prickling sensation at the back of the neck; at that point, the character must make a Constitution check (by rolling his Constitution score or lower on 1d20). If the check succeeds, the moss is unable to establish a feeding link, but it will continue to try to magically attach itself until the intended victim leaves its area of effect, requiring subsequent Constitution checks each round until that happens. If and when the victim fails a check, the moss is able to “latch one”, and it immediately begins feeding at the rate of 1 hp per round until the victim dies, until he leaves the area, or until the moss has consumed four times its own hit-point total in life energy (16 hit points), at which time it is sated and releases its victim. If several vampire mosses attack a single character, the damage can mount quickly; these creatures always attempt to establish feeding contact with the nearest being.

If a victim is reduced to half his or her maximum number of hit points as a result of the vampire moss’s feedings he must make another successful Constitution check or fall unconscious. Even if the victim makes a successful check, he must continue to make checks each round until the draining stops or unconsciousness. (Of course, the Dungeon Master should not at any time inform the character why the checks are necessary or what the results of failing them are until they occur. Nor should the DM identify the source of the energy drain.) The victim dies when reduced to 0 hp.

Meanwhile, as the moss feeds, it turns a brighter and brighter shade of green. A fully sated moss is a vivid emerald green.

The only ways to kill vampire moss are by ripping it into tiny shreds or by burning it. The moss regenerates all other damage at a rate of 2 hp per week.

Ecology: Vampire moss serves no particular purpose in the ecology of the swamp or forest; it’s more of a parasite than anything else. Unfortunately, it does not die if deprived of higher life forms upon which to feed – the moss can even feed upon the life energies of nearby trees, but it only does so if on the verge of starvation.

Vampire moss may be used as a component of energy draining magic such as cursed potions of harm (reverse of healing) or rings of weakness.