The le-matya (sometimes written le'matya) was a predatory animal lifeform native to planet Vulcan. They were distinguished by their large size and poisonous claws. (TAS episode & Log One novelization: Yesteryear)
These were a fierce green, yellow or orange-skinned hunting cat that inhabited various regions on the homeworld of the Vulcan civilization. The le-matya was known for its lightning-fast reflexes and poison-tipped claws. The cats were known to attack anything they saw or smelled. The deadly nerve toxins in their claws were capable of killing a small animal within minutes, or paralyzing a humanoid. Because they attacked anything they encounter whether they were hungry or not, no le-matya were allowed on any of Vulcan's nature preserves—if one entered onto a preserve it was removed as quickly as possible.
Le-matya were known to live in the deserts near ShiKahr, the Valley of the Seven Winds, and travelers beyond the city's walls should take care. Le-matya that lived in the volcanic plains tended to be larger and even more aggressive toward Vulcans they might encounter, killing solely so they can drink the blood of their victims. Specimens as large as 90 kilograms had been reported in the vicinity of the Cheleb-khor desert. (Last Unicorn RPG module: The Way of Kolinahr: The Vulcans; SA comic: "Liberty")
Le-matya typically lived in the hills but did emerge in times of drought when native prey was sparse. In such times, Vulcans had to place traps for the creatures, as otherwise they were known to go into homes and even steal household pets. (TOS novel: Faces of Fire)
During the midsummer they roamed the desert widely where they sought water as the desert watering holes dried up. When they found prey, they killed to drink blood even when they were not hungry. (TOS novel: The Vulcan Academy Murders)
During a ceremony celebrating of the birth of Surak, at least six le-matya and a feral Vulcan boy attacked the participants. Stunning one particular le-matya triggered a painful reaction in the boy, who collapsed, and then the rest of the animals fled. The boy, S’Vol, was the son of Forge wildlife expert Tar’ak. S’Vol had disappeared months earlier in Vulcan’s Forge during his Kahs-wan maturity test and had been presumed dead. S’Vol had unique biology in that he had been born prematurely, with his mother dying in childbirth. To save his son’s life, Tar’ak combined his son’s DNA with the generic material of wildlife from the Forge, le-matya in particular. Injured during his Kahs-wan, S’Vol was discovered by a female le-matya. Sensitive to their shared DNA, it protected him as if it were her cub. This allowed them to share a psychic bond which awakened the boy’s animal DNA, driving him into a bestial state. (TOS - Kakan ni Shinkou comic: "Forging Alliances")