Piranha

Only sharks are more dreaded among fish. Piranhas usually run 8 to 10 inches long, with the biggest normal specimen ever measured at 2 feet. They are silver or black, with a serrated belly and rows of big triangular teeth that meet like shears.

They swim in shoals of 5 to 50. Anything that swims or wades nearby has a 75% chance of drawing at least one attack. A single bite hurts but seldom kills. The danger comes when a piranha draws blood: the whole shoal goes into a frenzy, and each fish attacks twice per round. As many as 20 can bite one man-sized creature at once.

Piranhas favor tropical waters and are most plentiful in great river systems. They are ruthless hunters and stay vicious even when flung onto land, though, like most fish, they smother within minutes out of water. Blood in the water draws them from afar and whips them into a mad feast.

Their normal food is other fish, but any animal entering their waters is fair game, and nothing hunts them. Their teeth shear off chunks of flesh with each bite. They can breed after only a few months, do so all year, and live about four years. They are not traded and have no use in magic, though primitive peoples sometimes wear their teeth as ornaments and wicked rulers and wizards stock castle moats with them.

Quipper: These are piranhas adapted to cool, temperate fresh water. They match normal piranhas in every way except breeding, which happens only in spring and summer. Dungeon builders sometimes put them in water traps.

Giant Piranha: Colored like their smaller kin but much longer and very fast, giant piranhas are 95% likely to send at least one fish after anything swimming or wading near the shoal. Blood sends them into the same frenzy of two attacks per round, and as many as eight may swarm one man-sized foe. They are nicknamed sky-eaters because once per round one may race forward and launch itself up to 10 feet out of the water, usually at low-flying waterfowl but sometimes at people. They are silver with dark bands, breed far more slowly than normal piranhas and live longer, 8 to 10 years.