The Tarr

Slimeology:

''The Tarr are formed when a largo eats a plort unlike the ones it produces (ex. a pink tabby largo eats a honey plort). A terrible transformation occurs that turns the slime into a sludge filled with a swirling, prismatic array of colors and a relentless appetite. The Tarr seek only to consume and replicate. Because of this it can spread rapidly throughout the ranch.''

''The only way to stop a Tarr (outside of incinerating it or throwing it into the slime sea) is with fresh water. One splash will stop a Tarr from spawning new Tarr, and repeated splashes will destroy it entirely. However, one splash of fresh water does not kill the Tarr and it will continue to expand. ''

Alternatively, many ranchers recommend running away with their arms waving, screaming.

Rancher Risks:

''The Tarr are the single biggest threat to ranchers. The Tarr will seek out slimes to consume and replicate themselves, but also devour chickens, rot crops in their proximity, and even devour ranchers!''

Plortonomics:

''The Tarr produce no plorts, only more Tarr. And then more Tarr still.''

Tips

 * Ranching largos may be highly profitable, but one stray plort and you could wind up with a devastating Tarr outbreak.
 * However, the easiest way to do it is to put them in the Grotto, since even if you get a Tarr outbreak, they can't get in and out of it. They're trapped.
 * The Tarr produce no plorts to sell. You can enclose them in a corral but they will die shortly after.
 * Using water on the Tarr just once will stop them from reproducing as indicated by loss of its rainbow colors.
 * You can know when a Tarr just got hit by water when it flashes red.
 * Certain areas are more prone to Tarrs than others. The last area of the Dry Reef, for example, often gets filled with Tarrs because all 3 diurnal slimes that live in the Dry Reef (Pink Slimes, Rock Slimes, and Tabby Slimes) spawn there. The Moss Blanket has more slime types, so Tarrs also have a high chance of happening there, but luckily water is common there as well, so it's easy to get rid of them.
 * If you don't have water when encountering a Tarr, you can use your vacpack to toss it into the ocean.
 * If you manage to hold onto a Tarr for 15 seconds, you get the Achievement: Once Bitten, Twice...Bitten.
 * Puddle plorts will also kill Tarr, and unlike water, they can be stored in a silo. Some ranchers have used this to turn The Grotto into a Tarr shooting range.
 * You can use Tarrs to stop any Feral Slimes.
 * However, Tarrs may be more likely to reproduce from eating these slimes.
 * Having Water Tank upgrade is required if you want to fight it with water.
 * The Tarr's nearby presence can be implied by sudden change of music.
 * If for some reason you don't have music, they can be heard from the pleading noises of slimes being attacked. It sounds somewhat like a soft 'Paah! Paaah!"

Trivia

 * Tarr is an acronym for Those Awful Ravenous Rainbows.
 * Tarr may also be a reference to tar (black mixture of hydrocarbons and carbon).
 * In the prototype versions, the Tarr's design was very different from what we have today. It was a dark brown slime that always had a drooling expression and dark red eyes. You can take a look at it here.

Changes

 * 0.3.5: Flashes red each time it is hit with water.
 * 0.3.0: Now when it dies, it produces a rainbow explosion.
 * 0.2.5: A bug causing their music to still play after them disappearing has been fixed.
 * 0.2.3: Tarrs now react to being in water as if they were hit with it.
 * Before 0.2.0: Added.