Tales of Tolgard
Luck eaters look like slender, short-haired domestic cats with golden or black fur. They are wholly unable to inflict physical damage on another creature.
When encountered, a luck eater begins to purr softly, causing all creatures within 30 feet to become attracted to the animal. Those under the creatures spell want to bring it with them and protect it from harm. The luck eater always permits this, staying for several hours, purring all the time.
While the luck eater is with a party, all creatures within its range suffer in their efforts to hurt the benefactors. In addition, all damage they inflict on the party is reduced by 10%. In some unknown way, the luck eater is able to feed itself with the shifts in probability it induces.
If the luck eaters companions have not fed it within three turns (that is, nothing is attempted by anyone within 30 feet of the creature), it alters its purr slightly. Those affected attack the next creature they encounter.
If the luck eater continues unfed for another 30 minutes, it alters its purr once again. This time, those affected attack the nearest creature (friend or foe), excepting only the luck eater itself. This battle continues for for about a minute or until a death occurs. The luck eater always slips away during the melee.
In any event, the luck eater departs after two to five hours in the company of its benefactors. Those previously attracted to the luck eater regain their senses in no more than a minute after leaving the animal’s aura.