Large cat-like predators native to the deserts of Vulcan, armed with poisonous claws, one of which attacked the young Spock during his self-imposed survival test and fatally wounded his pet sehlat.
The le-matya is a Vulcan desert carnivore seen in the Animated Series episode Yesteryear, written by D.C. Fontana. It resembles a big mountain cat with a scaly, patterned hide, and its claws carry a poison that is deadly without quick treatment.
In the episode, Spock travels back through the Guardian of Forever to his own childhood, posing as a cousin named Selek, to repair a timeline in which he died as a boy. The seven-year-old Spock sets out into the desert near ShiKahr to prove himself, and a le-matya attacks him in the night.
His old sehlat, I-Chaya, fights the animal until the adult Spock arrives and subdues it with a nerve pinch, but I-Chaya has been clawed. The boy crosses the desert to fetch a healer and then makes the choice to let his pet die peacefully, a decision that sets him on the Vulcan path.