This is a Slime Science Advanced DLC item.

Slime Breeding

Slime Breeding is an activity first unlocked when the Slime Lab is purchased. Once it is avalible, the Slime Breeding Grounds option is added to the Plot GUI. The process begins once two compatible slimes, largos, or food items are inserted. Within 1-2 Slime Rancher days (0.5 - 1 when the Music Box upgrade is purchased), a new slime will join the breeding pair, and the process will not restart until only two remain. 

Breeding Grounds Upgrades

Shade Structure - 800 NB - Protects light-sensitive slimes from the sun.

Nuclear Sponge - 750 NB - Reduces radiation.

Music Box - 900 NB - Cuts breeding time in half, stops Tarr aggression (allowing for slime-tarr breeding)

Breeding Pond - 600 NB - Stops Rad Auras and allows water-dependent slimes to be bred.

Tarr Shield - 500 NB - Keeps all kinds of Tarrs from leaving the breeding grounds, allowing Tarrs to be bred.

Windlock - 550 NB - Stops slimes that are weak to the wind (Such as Dust Slimes) from blowing away.

Compatible Slimes, largos, and/or food items:

If two slimes of the same breed are paired, the offspring will be the same breed. Of course, some breeding pairs, such as Puddle Slimes and Phosphor Slimes require special upgrades.

If not already a special breeding pair, two slimes of different types will produce an offspring, being a largo of both types. Of course, this rule does not apply when breeding Tarrs or Largos.

Special breeding pairs:

Member One

Member Two Result Required Upgrades

Success Chance

Boom-Rad Largo Rad Slime Nuke Slime Nuclear Sponge 70%
Mosaic Slime Puddle Slime Ancient Puddle Slime Breeding Pond 2%
Crystal Slime Puddle Slime Radiant Slime Breeding Pond 50%

Genetic Mutation

Another benefit (or not) of slime breeding is Genetic Mutations. Genetic Mutations are strange properties applied to baby slimes when they are born that can be manipulated via Slime Genetics. For example, some slimes will turn strange colors, or even develop bodily toxins and have the ability to kill Tarrs that eat them. There is a 15% chance one will affect a Slime.

When two slimes are bred, one or more of them with a mutation, there will be a more than 50% chance that the offspring will also show that trait.When a baby is born with a mutation, it will always gain the Miscolor trait.

Positive Mutations:

Toxic Blood - Kills Tarrs that eat them. (Does not affect Gold Tarrs)

Trilargo - When two slimes of the same species breed, there is a chance the offspring will be twice as big and produce three plorts when fed, and six plorts when fed their favorite food.

Tiny! - Makes the offspring 2x as small as the parents. Allows for more slimes per Corral.

Neutral Mutations:

Miscolor - Gives the slime a completely different color.

Negative Mutations:

Big... - Makes the offspring 2x as large as the parents.

Plortless - Eats, but does not give plorts.

Bouncy - Jumps 2x as high as normal.

Exclusive Mutations:

Phosphor Slime:

Solar Absorbent - Phosphor Slimes have a stronger glow and can stay in the sun. (Positive)


Defused - Cannot explode (Positive)

Extra Strength - Has a 2x larger explosion radius. (Negative)

Rad Slime:

Uranium-ized - Has a 1.5x bigger Rad Aura radius. (Negative)


Breeder! - Use the Breeding Grounds.

Playing with Fire - Breed two Tarrs.

Isn't that strange? - Get a Genetic Mutation.


  • Breeding is the only way to get Largos involving Puddle Slimes and other water-dependent slimes
  • Mochi Miles claims she once successfully bred a Gold Slime and Tarr.
  • Crystal Slimes' Plorts are thought to aid in breeding. However, this was disproven when Ogden Ortiz tried breeding two Pink Slimes, and they were terrified of the spiky plorts.

Terms of Use

This idea is not free to use.