Leether Slime

This doesn't exists in Minecraft, It's just Fiction

Leether Slime,' Leethers' Goo or Golden Blob' is a Hostile Mob and a Slime found only in the Leethers. They are way stronger than any Slime or Magma Cube. It cannot die in Lava nor Water unless drowned. When killed they drop Leether Cream and xp.

Tactics
These Slimes are more dangerous than any Slime, even Magma Cubes. They are the strongest Slime in Minecraft. They can kill an Enderman with an OTK, when you get them to try and lash you but hits the Enderman and kill it. They are a bit bigger and smarter than slimes. To kill one fast you need a Golden Sword.