"The Unstable Gordo was a result of many rad and boom slimes congregating at once. The result was... Not entirely the best, to say the least."    Template:Slime Infobox

It is found in the cave of the Indigo Quarry, (The one with the Rock Gordo) and only appears when you have discovered boom and rad slimes, and popped the Rock Gordo. Once you have done all of these requirements, when you go into the cave, a cutscene will happen. It shows many Rad and Boom slimes gathering together. Then, after they gather, an explosion happens, and the Unstable Gordo rises from the ground, with a defeaning roar. This music plays.

While the fight happens, a pond will appear at the edge of the cave. Water can be launched at the Unstable Gordo to weaken him.


Largo Summon

Summons up to 8 Feral Rad Boom largos.


The cave becomes extremely dark, with only your vac gun serving as light. This lasts for 25 seconds.

Rad Field

A rad field appears around the Unstable Gordo. It keeps growing, forcing you to go to the edge.

Molten Massacre

A bunch of Boom Slimes home in on you from the ceiling. This is often paired with blackout.


Rad largos will appear, which are largos of your vacpacced slimes. (For example, if you had a Tabby Slime in your vacpack, a Rad Tabby largo would appear. No slimes are taken from the vacpack.) (If you have no slimes in your vacpack, 3 randomly picked rad largos will appear.)

Plort Overload

The Unstable Gordo throws Boom plorts at you, which explode on contact with you.

Nuclear Destruction 

Rad Slimes rain from the ceiling, with twice as large auras. Feral Pink Boom largos follow you.

Quarry Collapse 

The Unstable Gordo bounces on the ground, shaking the cave. A point (Usually where the player is.) is marked with a giant red exclamation mark. This point falls after 5 seconds. 


The Unstable Gordo's rad field closes in on itself, and the Unstable Gordo explodes. A crate appears, containing a Gold Slime, 2-3 Rad Slimes and 1 Boom Slime. There are also many rad and boom plorts scattered on the ground.


  • Originally, it was going to be a rad-rock combination.
  • Blackout was inspired by the horror game Tattletail.
  • There was a planned easter egg that would end the battle by having  the Gordo like you when you feed it enough. This was scrapped because the fight would've been to easy.
  • Originally, you would have to throw Boom Slimes instead of water.
  • There's actually TWO CAVES behind the rock gordo. One leading to the boss and one leading to the slime hero stickman king 28. (Not to be confused with the user.)