El Lobizon is Argentina's werewolf, a cursed human who periodically transforms into a large, ferocious animal that resembles a large-eared dog, with legs like those of a child. According to local legend, only the seventh son in a family whose children are all boys can fall victim to this curse.

El Lobizon appears only when there's a full moon, and legend has it that the stricken man is especially likely to transform when that full moon falls on a Friday. Tales of run-ins with the beast suggest that it's quite difficult to subdue, shrugging off blows with blunt objects as if they didn't even occur.