Curse of Midas

When found in long forgotten ruins, the Curse of Midas is commonly seen as a Large pool of golden liquid or as a Large pile of Gold coins, only when it is moving will its real shape be seen. This Golden globule shaped semi-intelligent ooze that often enjoys luring in adventurers with gold, only to engulf them and add to its collection, they vary in size from Tiny to gargantuan. When killed one Small Midas ooze splits into four, a Medium one into six, Large into eight, Huge into ten, and gargantuan into a Minimum of twelve or twenty..., can a Curse of Midas ooze be killed permanently? yes, how do you do it?, you kill the tiny Midas oozes before they grow any bigger, and why doesn't this happen? because adventurers love gold and taming a tiny Midas allows you to turn ordinary metals into gold. 

"Even though training a tiny Midas ooze can be rewording to an adventurer in and of itself, when that adventurer dies, do you think the ooze isn't going to turn back into a mass murdering monster?, yes it is true that a tiny sized Midas can be permanently kept as a tiny pet, but that requires you to have a 9th level remove curse spell cast on it which isn't cheap, I remember the local clerics charging fifty five platinum for one Midas cleansing. If one huge sized Midas ooze can split into ten separate tiny Midas oozes and lets say 6 of them grow up to be huge like their parent, then when another group of adventurers go into that ruined city and manage to only catch three of the fleeing tiny slimes out of the sixty they caused the births of, then we will have an epidemic on our hands" - Laurie Olly, Loxodon Paladin & Beast Chronicler

Curse of Midas oozes dwell in ancient and abandoned ruins at the frayed edges of olden civilization. A Curse of Midas ooze’s lair   in ancient broken down temples, old dungeons tunnels and in abandoned city streets, and where its victims can be on display as gold statues. The lair is littered with puddles and pools of gold, watched over by crumbling statues. Non-metal gear can be found everywhere in the lair, which is filled with the strong stench of iron and dust.

Lair Actions
On initiative count 18 (losing initiative ties), the ooze takes a lair action to cause one of the following effects; the ooze can’t use the same effect two rounds in a row:

• Any water that the ooze can sense within 80 feet of it turn acidic. Any creature drinking out of a waterskin, touching or just wadding through a pool or puddle on the ground must succeed on a DC 16 Constitution saving throw, taking 3d6 acid damage on a failed save.
• A mass of swarming golden insects fills a 20-foot-radius sphere centered on a point the ooze chooses within 80 feet of it. The swarm attacks all creatures of the oozes choosing and remain until the ooze dismisses them as an action, uses this lair action again, or dies. The swarm uses a base swarm of insects with an AC of 16 and a hitpoint total of 38. Any creature near the swarm when it appears must make on a DC 15 Constitution saving throw, taking 10 (3d6) piercing damage on a failed save, or half as much damage on a successful one. A creature that ends its turn within 5-feet of the swarm takes 10 (3d6) piercing damage.

Regional Effects
The region containing a legendary Curse of Midas ooze’s lair is warped by the ooze’s stagnant magic, which creates one or more of the following effects:

• The land within 3 miles of the lair takes twice as long as normal to traverse, since the mud is thick and the puddles go 5 feet deep, and the ponds are filled with unnormally aggressive quipper's.
• Water sources within 1.5 miles of the lair supernaturally glow of a strange oily substance. Enemies of the ooze that drink such water suffer 1 point of exhaustion as they find it increasingly hard to breath within minutes after drinking.
• A fog lightly obscures the land within 4 miles of the lair.

If the ooze dies, the murky water remains as it has settled, but other effects fade over 1d10 days.