I write this as someone who lost about 36 hour this week to what the doctors claim was the flu, but what I know was actually an invisibile monster.
The Flu Bug
No. Appearing: 1 (see below)
Armor Class: 8
Hit Dice: 1
% in Lair: Nil
Treasure Type: Nil
No. of Attacks: 4
Special Attacks: Disease
Special Defenses: See below
Magic Resistance: See below
Size: S (about 1′ diameter)
Psionic Ability: Nil
Attack/Defense Modes: Nil
Level/X.P. Value: III/61 + 1/hp
The flu bug is a dreaded monster that appears seasonly in many parts of the world. It skulks about, usually airborne, relying on its natural invisibility and amorphous form to squeeze through small spaces in order to infiltrate buildings where people live and work. The worst part about the flu bug is that killing it might make it all the more dangerous.
Since flu bugs are normally invisibile, they gain the advantage of subtracting 4 from “to hit” dice rolls of all opponents unable to detect them. Flu bugs can attack while invisible. They do so striking with their frail-looking arms. These attacks inflict no damage, but the creature struck must make a saving throw versus poison with a -1 penalty per successful attack by the flu bug that round. Failure means the creature contracts a disease. Once a flu bug has infected a victim, the flu bug dies, having fulfilled its purpose. Flu bugs that die this way do not spawn (see below).
Flu bugs can be harmed by normal weapons, but they are immune to most magic. Spells that cure wounds or disease affect flu bugs. A cure wounds spell causes damage to a flu bug equal to the amount the spell would normally cure. A cure disease slays the flu bug immediately (no save), and prevents the flu bug from spawning. Otherwise, when a flu bug is killed, it spawns a number of new flu bugs equal to the original monster’s hit points unless the area in which the flu bug died, including everyone and everything it came into contact with, is thoroughly sanitized. These new flu bugs spawn in 1d4 hours, and gain 1 hit point per hour thereafter until they reach whatever their maximum hit points might be.
The disease caused by the flu bug is debilitating and potentially fatal. Each day for the 3-8 days, the victim suffers these effects:
* A cumulative 10% loss of hit points due to weakness and fatigue.
* The loss of 2 points from both Strength and Constitution due to joint pain, vomiting, and difficulty breathing.
* The loss of 1 point of Dexterity due to dizziness.
* Difficulty concentrating due to high fever, imposing a 10% cumulative chance of miscasting spells.
Total bed rest helps mitigate these effects, making it only 50% likely that each will occur each day of the illness. Victims are also highly contagious. Double the normal modifier for “exposure to carrier of communicable disease” (from +10% to +20%, as explained on page 13, Dungeon Masters Guide). A cure disease spell removes the disease from the victim, but does not remove the effects of the disease. Those fade at the same rate by which they accrued.