B/X Monsters A to Z: Fish, Giant

 No fish stories here; these monstrous swimmers really are found in the D&D Expert Rules set. Four varieties of giant fish are described: piranha, rockfish, catfish, and sturgeon. (It's interesting to note that B/X's successor, the Mentzer/BECMI Expert Rules set, lists three kinds, doing away with the piranha and catfish and adding the giant bass.)

Giant Piranha: Much bigger versions of the classic Amazon River terrors, these piranhas are around five feet long and have a respectable AC 6 and 3+3 Hit Dice, placing them above the average warhorse in toughness. From 2-8 of these fish will be encountered. They will attack any disturbance in the water near them, and up to eight can attack a single man-sized target at once, dealing out 1-8 points of damage with each successful attack. Morale is listed as 7, but once blood is drawn, they go into a frenzy and no longer check morale. Piranha are found in warm freshwater, rivers or occasionally lakes.

Giant Rockfish: Denizens of shallow coastal waters, the rockfish resembles an ordinary boulder or mound of coral. Curiously, out of the four fish under the heading, the rockfish is not given any physical dimensions, so we can only guess at how large it might be. The rockfish isn't especially aggressive or hostile, but will attack if disturbed. It has an AC of 7 and a whopping 5+5 Hit Dice. The latter number is interesting for the fact that it's one of, if not the highest, plus to the HD of any creature in the rules. (B/X, when it uses pluses at all, mostly sticks to +1, with a smattering of +2s and +3s, and no +4 to be found at all.) Incidentally, that makes the giant rockfish a fair bit tougher than the grizzly bear or owlbear, both at a straight 5 HD. The fish attacks up to four times with its spines, dealing 1-4 points of damage each but also inflicting a save-or-die poison on each successful strike. You might expect a fish resembling a rock to be relatively slow, but it gets a very swift 180'(60') movement rate. Morale is solid at 8.

Giant Catfish: Described as chalky white and about 15 feet long, the giant catfish is found on muddy lake and river bottoms. For some reason, this catfish is rather heavily armored, with an AC of 4, and has an impressive 8+3 Hit Dice, placing it in the same league as such behemoths as elephants and the middle ranks of dragons. In combat, it can bite for 2-16 damage and also attacks with four "feelers" for 1-4 damage each. I'm not sure if the authors are taking some major artistic license here or if they're truly ignorant of the biology of real world catfish, but the fish's barbels, or "feelers," are sensory organs, helping it to find food in murky water, not forms of attack. Even if you drop those four extra attacks, a giant catfish is still quite formidable, so it's fortunate only 1-2 will be encountered at a time. Its morale is a very average 8. It is much slower than the other giant fish, at only 90'(30') but to adventurers who will be moving at half-speed in the water, that probably hardly matters.

Giant Sturgeon: The real monster of the giant fish world, and a creature with which the authors have taken A LOT of artistic liberty. More on that below, but first, the monster as written. It's described as being nearly 30 feet long, covered with thick, armor-like scales, and a vicious fighter. Its listed AC of 0 is on par with some of the tougher dragons, and its 10+2 Hit Dice make it more durable than most dragons, and certainly more than the great white shark, its nearest match among D&D fish. It bites for 2-20 points of damage, and swallows prey whole on a roll of 18 or better. (No mention of a limit on prey size, but presumably at least up to man-sized.) Its Morale score of 9 represents a tenacious fighter, and its movement rate of 180'(60') means that few aquatic creatures, never mind land-based adventurers out of their element, will escape its ravenous maw.

Real world sturgeons have been known to grow over 20 feet, but average 7-12 feet; nonetheless, even the larger ones have never been known to swallow human-sized prey, so it seems unlikely that one only 50% longer would manage the feat easily. Also, while the monster description seems to imply a gaping maw full of sharp teeth, sturgeons actually have toothless sucker mouths designed for bottom feeding on smaller fish, mollusks, and crustaceans. It's quite a stretch indeed to imagine them biting for the same damage as the notorious great white shark. Finally, real sturgeons do indeed have rows of bony plates embedded in their hides, but it seems absurd that it should afford better protection than plate armor or dragon scales.

I'll suction you for 2d10!

It turns out, my opinions on giant fish are a lot stronger than on most other monsters. They're way overpowered in my opinion, and while other monstrous versions of real world creatures arguably do a poor job modeling their abilities, some of these fish have purely fantastic abilities. 

I'd tone the giant piranha way down, to AC 7, 1-1 HD, and 1-4 points of damage, but I'd raise the number appearing to 3-30 and say up to 12 may attack a single target. That seems suitably fearsome to me. Real piranhas range from 5-14 inches in length; 12-24 inches seems like a good range for the giant variety. Real piranhas are also not as voracious as they're often portrayed, but it doesn't feel unreasonable that giant ones might be meaner as well as bigger.

The giant rockfish isn't too bad as-is, though I might drop its Hit Dice to 3 or 4. Otherwise, I'm pretty satisfied with it.

Giant catfish seem too tough, and if I'm going to reduce rockfish HD, it seems fair to pass the 5 HD on to the catfish. An AC of 6 seems more in line with how I think of fish skin. Also, nix the "feeler" attacks; instead, its sensory acuity enables it to attack without penalty in blindingly murky water or darkness.

Giant sturgeon... well, I'm not even sure where to begin. A toothless, sucker-mouthed fish doesn't exactly paint a picture of a fearsome foe. It may be a "vicious fighter" when fighting for its freedom when hooked by an angler, but is it a killer? No, it's not. Maybe a tail-slap attack for 2-12 points and a Morale of 6 would be more fitting? I'd probably be inclined to scrap it altogether, honestly.

As some bonus content, let's look at the Giant Bass from the Mentzer Expert rules. This is actually, in my opinion, a much better-designed creature than most of what Cook and Marsh gave us. The giant bass has an AC of 7 and 2 Hit Dice, making it of impressive size for a fish but not outlandishly absurd. I imagine it being around the size of a large dog. Its damage of 1-6 might be a tad on the high side; 1-4 might suit better, but I'm not too fussed about it. The description states it is normally shy and will only attack if something edible of halfling-size or smaller is floating nearby, or if summoned to fight by nixies. Its movement rate is a sound but not crazy 120'(40'), very credible for a chunky-bodied fish known to inhabit bodies of water without swift currents such as lakes and ponds. Its Morale of 8 suggests it's tenacious once engaged. With minor modifications to damage or movement rate, the giant bass could be tweaked to represent giant trout, perch, or bluegill too. Altogether, an excellent, if niche, addition to the D&D bestiary. Well done, Frank.