Parallel drainage pattern. A parallel drainage system is a pattern of rivers caused by steep slopes with some relief. Because of the steep slopes, the streams are swift and straight, with very few tributaries, and all flow in the same direction.
1 In Creative, the player can use spawn eggs to spawn most mobs. 2  When mobs are spawned this way, all normal spawning requirements, such as light level and block type, are ignored. 3  Any entity can be spawned using the /summon command.
1 Slimes will only spawn if they are in any eligible chunk under layer 40, or in a swamp biome at a low light level. 2  In the Nether, the locations are less varied, 3  Skeletons, wither skeletons, and blazes can spawn within Nether fortresses.