Zombies have been replaced with red bears and red wolves. "You hate them. We know. They're just plugging a gap for now. All will be revvvealed," Facepunch writes in the update description.
The update also makes wildlife act more realistically: Animals will be spooked by gunshots and docile wildlife now fear predators. On top of that, some general bugs have been squashed, some animations have been tweaked and workbenches now allow you to craft items faster when standing next to them.
Rust has sold over 750,000 copies since its launch on Steam Early Access in December. Rust was created by Garry Newman, of Garry's Mod fame, and is currently available as a $20 alpha on PC, Mac and Linux.