The creature attacks by willing a tumor to grow in a target within 100’, and it accomplishes this with a normal to-hit roll. Targets which are hit grow a tumor of some size. Roll 1d4 to determine this tumor’s “size factor.” This is the amount of encumbrance points the tumor adds to the target and the chances in 6 that, when the character is successfully attacked, the attack hits the tumor.
If a tumor is hit, the character takes normal damage from the attack plus the same damage again as the trauma causes the tumor to release toxins into the character’s body. (This will happen every time the character is damaged by an area effect attack as well.) Then the
victim must make a saving throw versus Poison, or suffer 1d4 more points of damage.
Keep track of the damage the character suffers due to those failed Poison saves. When the amount cumulatively suffered by that specific type of damage (even if some is healed along the way) equals the character’s maximum Hit Points, the character is taken over by the tumor and transforms into a living mass of cancer. Game over.
The victim’s tumors have eyes all over them in the same manner that the creature itself does. The creature can see out of the eyes on its victims’ tumors.
A tumor can be reduced in size each time a healing spell of any type is specifically cast on the tumor—for each 6 that comes up on the die rolls for the healing spell, the tumor shrinks one size. Such applications of the healing do only affect the tumor and do not heal damage. If a character is exposed to radiation, a saving throw versus Poison will also shrink a tumor one size. Time may also change the size of a tumor. Every month the character should save versus Poison. If the save is successful, the tumor shrinks a size, if the roll is less than half of what would have been needed, the tumor grows one size. When the tumor is at size factor zero, it is gone permanently.
The creature does not technically exist by any measure other than “I can see it!” and so it may sense and move through solid objects as if they were not there. Physical objects pass through it and existing on six dimensions simultaneously (none of them this one except as a mirage) it is even immune to all magic.
The creature is itself harmed by magical attacks made against the tumors of its victims, including physical attacks made with magic weapons. These
attacks do damage to both the victim and the creature.
This beast is almost more of a force of nature than it is a monster. Encountering it is like encountering an avalanche or an erupting volcano. The most sound strategy is to flee from it. If you try to fight something like that, you end up buried in snow, melted to slag, or in this case, riddled with cancer.
The Defender’s second creature isn’t quite as invulnerable as it might seem at first. Like other monsters from this series, there is an obscure trick which allows it to be defeated easily if the trick is discovered. Unlike the other creatures, that trick is really the only way to kill the thing. Nothing else will work. In most cases, I would say that’s poor monster design. A game of “guess what the GM is thinking,” which is never fun.
However, there are a few mitigating factors here. First, the creature has no real attacks. It can create tumors, and the tumors are dangerous, but they’re more of a long term danger. The players have as much time as they need to think about the tumors, and what to do with them. The only time the tumors actually put the character’s life in danger is when the character is the subject of attack. And if the character is being attacked, then their life is in danger anyway. The cancer is more of an imposed vulnerability than it is an attack.
Second, the creature’s completely immaterial nature (literally nothing in this world seems to exist for it) should make it very quickly obvious to any competent group of players that they need to retreat. When the players are informed that their weapons pass through it as though it were an illusion–as do their spells, magic items, and other methods of attack–then if they don’t retreat to reassess the situation, they’re being foolish. Likely some member of their party will be cancerous by this point, but as stated above, the cancer isn’t really that dangerous unless the group decides to ignore it entirely.
And once the players do flee from this beast, the fact that the eye-covered cancerous growths look very much like a corporeal version of the creature they just fled from seems to me a very good indication that they should stab it.
One thing I’d be curious to know is how much of the treatment information the players ought to be able to find in their world. If the cleric says “I want to try to cure this cancer, how do I do that?” should the GM tell them that casting healing spells directly on the tumor might have some effect, or is that something the players need to decipher for themselves? Personally, I’d tell my players that sort of thing, but I wonder if that is what was intended.
This is easily my favorite monster from the module.