Savanna

Savanna (also referred to as Plains) is a type of biome that is rich with Grass and Mobs, while containing little flora. It is the only known biome to spawn Beefalos, but it is also host to many Rabbits, Redbirds and Crows. Spiders may also rarely appear. Flowers are sometimes found, which spawn Butterflies, but this is rare.

While a lot of grass tends to grow on this terrain, Trees don't spawn on a savanna, unless the savanna the tree is on is close to another terrain on which trees can grow. It is, however, possible to manually plant trees on a savanna.

A savanna can differ in size from a few tiles to an entire island, but Beefalos don't tend to spawn unless there are at least around 25 tiles present.

Trivia

 * Savanna is probably the best biome to settle in due to abundance of ever needed grass, renewable food sources and close proximity to beefalos. While other essential renewable resources such as twigs and trees can be easily transplanted from other biomes.