What other organisms interact with the saber-toothed tiger?

There were many different species of saber toothed cat, and each one lived in a different place and/or time between 23 million to 10,000 years ago. Thus, each species of saber toothed cat interacted with a different variety of species.

The most famous type of saber toothed cat, Smilodon fatalis, lived in North America up until 10,000 years ago. So they lived alongside the same animals and plants that live in North America today, as well as some species of extinct animals such as the Columbian mammoth, camelops (American camel), giant ground sloth, glyptodon (a car-sized armadillo), American lions, flat-faced bears, Dire wolves, American horses (modern wild horses in North America actually are descended from European horses left behind in the colonial period), and many others. Around the time when Smilodon fatalis died out, humans arrived via the Bering Land Bridge, and thus they would have also interacted with the saber toothed cats.