An aquatic being recorded by Nahua informants in the Florentine Codex: doglike in outline, with slick fur, small pointed ears, and a long tail ending in a hand. From the water it could imitate the crying of a child, drawing a passerby close enough for the hand at its tail to seize them.
Accounts emphasize aftermath rather than spectacle. A recovered victim was said to be missing the eyes, teeth, and nails, and the death was treated as a selection by the rain and water powers rather than an ordinary drowning. That sacred context matters; the ahuizotl was more than a predator in a European bestiary sense.