A few Ideas, Scattered about.

[DDSilver]

The Goop
Like the Tarr, but much more Docile and... Goopy.
These poor largos decided to eat another plort, but rather than turning into an evil ball of rainbows, they turn into a sad puddle of slime.
Plort-O-Nomics: The Goop won't produce Plorts, but will take things slowly from your VacPac while you stand inside them.
Rancher Risks: One Goop can entirely empty a full VacPac, weather it be slimes, or food, they'll suck it up.

Cloud Slime (Why so Cirrus?)
Diet: Fruit. Favorite: Tomato Cherries
Slimeology: White and Fluffy, these slimes don't quite act like others. They prefer groups and quickly stop producing Plorts when alone. Keeping these slimes inside of a Corral isn't smart, they'll just float away! But they seem to enjoy being with other slimes to shade them from the sun.
Rancher Risks: Occasionally, when overfed, They'll get worked up and shoot out a bunch of water, and cease producing plorts for a while.
Plort-O-Nomics: Cloud plorts are light, and delicate, however, when compressed turn into an extremely soft pillowy substance. This makes them popular for money.

Tomato Cherry
Type: Fruit..?
Favored By: Cloud Slime
On the Ranch: Is it a Fruit? Is it a Vegetable? Who knows. Only fruit eating slimes will eat them though. They're pretty rare to find out in the Far Far Range, and can only be found in Boxes or by Trade.

Cloud Slime DETAILS (Not a Slimepedia type thing)
When one cloud slime is shot at another, they both cling together and share food. So you only have to feed one of the cloud slimes when they form a sheild over other slimes.
Also, When put in a slime corral, if the slimes get rowdy and jump up at them, they poof away.

[Sectanza]

I love both of these ideas! A corral of adorable fluffy cloud slimes would be awesome~
I also love how you played on the whole tomato fruit vs. veggie debate. Very clever! :D

[Tabbs4Days]

Awwwwww, poor Goopy. If only there were a way to cheer him up.