Cultivate players are able to use Spawners to spawn many different peaceful AND hostile mobs. Spawners and Spawn Eggs are accessible via the Item Shop (/shop).
Hostile Mobs WILL spawn in the Nether and the End. Hostile Mobs will not naturally spawn in the Overworld. In the Overworld, they can still spawn in via Spawners. Naturally generated Spawners can spawn hostile mobs, and this is why you might see SOME hostile mobs while in cave systems.
There are Mob limits in place on Cultivate. These limits are in place to reduce the lag caused by Mobs. They are a bit strict, due to Cultivate's lack of need for a lot of mobs in one area. While these limits were previously hidden to avoid exploitation, they are now going to be published and updated as they change. These limits ignore tamed and name-tagged animals. In ALL worlds, you cannot exceed:
10 of any Mob within a 4 block radius.
25 Pigs, Cows, Sheep or Chickens within a 10 block radius.
6 Turtles and Bees within a 5 block radius.
40 Villagers and Slime within a 50 block radius.
10 Zombie, Skeleton, Spiders, Cave Spiders, and Bees within a 3 block radius.
Spawners can be picked up with a Silk Touch pickaxe, by all players.
The mob type of a Spawner can be changed by right clicking a Spawn Egg onto a Spawner.
1 Spawner will cost $50,000 from the Item Shop. 1 Spawn Egg will cost $5,000.
Mobs and Mob Farms are typically not the main focus of Cultivate. Spawners are typically used only in the early game.