“Lankier than a cougar and longer in the leg, the highland cat the conquistadors named still prowls ranchers' tales.”
Mexican ranchers have long insisted the Sierra Madre Occidental holds three big cats, not two: the jaguar, the puma, and the onza — a cat built like a puma stretched thin, longer in the leg, lankier in the body, bigger in the ear, with faint dark markings inside its forelegs and a reputation for aggression neither of its cousins shares. Jesuit missionaries wrote about it in the eighteenth century; ranchers were still shooting specimens in the twentieth.
The onza matters because it came so close to being real. It has a name in Aztec-era accounts, a paper trail through colonial missions, and actual carcasses on examination tables — the 1986 Sinaloa specimen was measured, dissected, and finally genetically tested. The verdict, published in 1998, read: puma. The mountains kept their two cats, officially. Unofficially, the sierra's rancherías have never stopped seeing the third.
The Legend
The story begins in Moctezuma's menagerie. Bernal Díaz del Castillo's account of the Aztec ruler's zoo describes two kinds of 'lion': the familiar puma and a stranger, wolf-like cat — the animal onza proponents identify with the Aztec cuitlamiztli. Colonial missionaries knew it too: the Jesuit Ignaz Pfefferkorn wrote in 1757 that it was 'not as timid as the cougar, and he who ventures to attack it must be well on his guard,' and Father Johann Baegert recorded an onza attacking a boy in broad daylight.
Sierra folklore made the onza the dangerous one — bolder than the retiring puma, more willing to come down among stock and people, yet more elusive than either of its cousins. Ranchers and vaqueros in Sinaloa and Sonora treated it as a distinct animal with its own name and habits, and the legend passed down as practical knowledge: a lanky, long-eared cat that behaved wrong for a puma was an onza, and an onza was trouble.
Documented Sightings
The gun-and-skull record runs through the twentieth century. In 1938 Indiana banker Joseph Shirk, hunting with the famous cat hunters Dale and Clell Lee, shot a reputed onza on La Silla mountain in Sinaloa; Dale Lee insisted it was no puma, and the skull later vanished from the museum that received it. R.R.M. Carpenter took another that year in the same range, and in the mid-1970s Jesus Vega shot an onza whose skull passed to rancher Ricardo Urquijo — specimens enough to keep the question scientific rather than mythical.
The decisive animal came on January 1, 1986, when rancher Andres Rodriguez Murillo shot a large cat near Parrot Mountain in Sinaloa, fearing it was an attacking jaguar. It was female, about 60 pounds, 45 inches long with a 23-inch tail — long-limbed, slender, big-eared, faintly striped inside the forelegs. Cryptozoologist J. Richard Greenwell and biologist Troy Best had it examined at a regional laboratory in Mazatlán, and tissue samples went off for genetic analysis.
The Lore
The results, reported in 1998, were deflating: comparative protein work and mitochondrial DNA sequencing found the Rodriguez onza indistinguishable from North American pumas, and a peer-reviewed molecular study confirmed the identification. The onza, as far as molecules can say, is Puma concolor — perhaps a gracile local form, perhaps lean, sick, or simply atypical animals misread by frightened men in bad light.
Cryptozoologists such as Karl Shuker have kept a door ajar — one tested carcass, the argument runs, does not prove every onza was a puma — and the name still does work in the sierra, where a strange cat remains an onza whatever the gene labs say. The creature survives as a rare thing in cryptozoology: a legend with five centuries of documentation, real bodies, and a scientific answer that folklore has simply declined to accept.
Field Notes
- ✦ Spanish conquistadors recorded a distinct wolf-like 'lion' in Moctezuma's menagerie.
- ✦ A 1986 specimen from Sinaloa was studied and genetically matched to a normal puma.
- ✦ Belief in the Onza as a separate animal persists in rural folklore despite the findings.
- ✦ Jesuit missionary Ignaz Pfefferkorn warned in 1757 that it was 'not as timid as the cougar.'
- ✦ The 1986 animal weighed about 60 pounds — long-limbed, slender, and big-eared for a puma.
Case File
- Classification
- Mystery big cat
- Category
- Beast/Hybrid
- Territory
- Sierra Madre Occidental, northwestern Mexico
- First Sighted
- 16th century (Aztec accounts)
- Habitat
- Rugged mountain forest
- Reported Size
- Cougar-sized, lankier build
- Also Known As
- Cuitlamiztli · Mexican Mystery Cat