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.
Slimes also spawn below y-coordinates of 40 in specific chunks. Minecraft Wiki has a formula on the slime spawning mechanism and there are numerous tools to find slime-spawning chunks, however since it is subjected to change, it may be far easier and better to find slimes by simply look for swamp biomes on the ground.