Siberian tiger doesn't stand a chance even though it's heavier.
Sure - both are very fast with an advanced set of senses fit for locating, tracking, hunting and killing its prey, even in the dark. Adult Aliens however, are 7 to 8 feet tall, armored, pretty much impervious to fire and extreme heat/temperatures, have weaponized tails, can spit acid (at least some of them do), can climb and traverse walls & ceilings with ease, can beat up or even break through thick-ass bulkhead metal doors, plus they can one-hit kill most things with their inner jaws.
But let's say the tiger manages to bite or claw, effectively puncturing the Alien where there's a weak spot in the exoskeleton - then the tiger gets to deal with the horrific effects of the creature's acid for blood. It's going to turn the poor kitty's paws into smoldering stumps, or fry half its face off. While the tiger is trying to deal with the immense pain caused by the acid eating its paws/face away, the Alien will already be done recuperating, ready to swiftly kill the more or less incapacitated tiger.
I'd argue that there are no terrestrial land predators around that could kill or survive killing an adult Alien, NOT even an exceptionally large kodiak grizzly or polar bear.
If there would be a land animal that could kill an adult Alien and survive the encounter and the wounds, I'd say it's a stampeding African elephant bull stomping the Alien to death before the Alien has the chance to climb on top of it. Think of it as the APC in ALIENS ran over and crushed that Alien on the ground when the marines drove away escaping the hive. If I'm not completely wrong the APC weighs 15,000 pounds, which is the same as a really large male African elephant, so a nicely angled good stomp with most of the elephants weight on it, all against a hard surface, should crush the Alien fairly easily.
