It's a dinosaur that seemed to resemble both mammals and reptiles. However, I just learned that such an animal existed so here's a link that may be more informative then me.
http://www.washington.edu/newsroom/news/1998archive/12-98archive/k120898.html
he weights 350
Most of the time I wouldn't think so. The leopard is smaller and would probably try to attack the Gorgonopsid by jumping onto its back or side. The gorgonopsid skin would be tough and harder to rip through and if the Gorgonopsid was able to shake off the leopard and bite it then the fight would be over.
The late Permian, around 280 to 250 million years ago
There were many species of Gorgonopsids, and each one had a different weight.
Here's a list (Note that some are from the future and therefore made up) Series One: Gorgonopsid, Coelurosauravus, Scutosaurus, Arthropleura, Mesathelae, Mosasaurus, Hespironis, Dodo, Cestoid Parasite, Pteranodon, Anurognathus, Future Predator. Series Two: Deinonychus, Coelurosauravus, Pteranodon, Precambrian Worms, Smilodon, Mer Creatures, Silurian Scorpions, Silurian Millipedes, Colombian Mammoth, Scutosaurus, Future Predator, Arthropleura. Series Three: Pristichampus, Coelurosauravus, Future Predator, Camouflage Creature, Diictodon, Giganotosaurus, Future Fungus, Titanis, Dracorex, Megopteran, Embolotherium, Pteranodon, Australopithecus, possibly Acrocanthosaurus. Series Four: A pliosaur has been confirmed for Series Four. Species is unknown.