Rumor speaks of a wizard’s guild, secretive and nameless, that manipulated peasant, merchant, and king alike from its underground school deep beneath the city. Entering and leaving through the sewer pipes, the wizards remained cloaked in mystery for years. One day, a civil war broke out among their ranks. An evil necromancer, cruel and hungry for power, attempted to take over the school. By the end of that day, every other member of the guild died rather than submit to his rule.
In time, the necromancer met his own special doom. Old age overtook him, and he wasted away in the solitude of his underground kingdom. As the end approached, the necromancer began working frantically, trying to discover the secret of lichdom before death took him. He conducted experiment after foul experiment, and the waste from these projects was casually dumped into the sewer or thrown into a shadowy corner. With the last of his strength, the necromancer stirred his iron cauldron, staring hopefully at the crimson goop bubbling within. Without warning, the goop slithered out of the pot and rushed up the old wizard’s arm, enveloping him, plugging his nose, and surging into his mouth. It clung to his skin like a coat of blood. In seconds, the necromancers wicked spirit flew howling into Acheron.
Most people in the city above were cozily ignorant of these events. Indeed, no one would have learned of the necromancer’s experiments had he been more tidy. As it was, decades of alchemic pollution had permanently altered the denizens of the sewers. They had become tougher, smarter, and almost immune to magic. The first sign of trouble was when the rats fled to the surface…

Water cats are descended from the familiars of several of the wizards who died at the hands of the necromancer during his overthrow of the guild. Like many other creatures of the sewers, they have been warped by the magical pollution. Unlike most others, however, the cats are still benign and retain a strong affinity to man. Rumors speak of water cats guiding lost delvers back to the surface.

Combat: In many respects, water cats are unchanged from ordinary cats. They attack with their claws and bite, and these are not especially dangerous, except for their poison. Interestingly, water cats’ fangs are hollow like a snake’s, and poison is injected with every bite. If a save vs. poison fails, the victim is affected as by the 2nd-level Wizard spell ray of enfeeblement. Furthermore, human, demi-human, or humanoid victims must make a second save or gradually transform into a mongrelman over the period of a month. Rats, giant rats, wererats, and other rat creatures are slain instantly upon a failed saving throw. Water cats are the prominent cause of so many giant rats fleeing the sewers recently; normal rats are better at avoiding their predators, but many of them have also fled to the relative safety of the surface.

Habitat/Society: Water cats, true to their name, live in and around water. Unlike their normal cousins, they have no qualms about getting wet. They are secretive creatures who rarely allow themselves to be seen. Water cats rarely interact with others of their kind, except for mating. They communicate with each other in the manner of normal cats, but a select few actually understand common, a gift from their extraordinary forebears.

Ecology: Rats, mice, and other small mammals make up the majority of the water cat’s food, but occasionally they will nibble on a fallen monster or other creature. Water cats serve admirably to limit the rat population, and should one ever be captured and taken to the surface, it would make an incomparable mouser