The following is a list of character universes, their plot summaries, and their AUs. 

(!!!Some descriptions may contain spoilers!!!)

Humanoid Universe-

Known Characters in this Universe: Taimu Kīpā, Mazenta Nami, Fajī Ashi, Una Ki, Ita Zura, Kashi Koidesu, Kokoro Nouta, Yami Rozū, Yami's "Army"

Seven humanlike creatures (an intelligent human, an athletic robot, a shy mermaid, a fierce neko, a chill peacock-girl, and a pair of chimera shapeshifters) live together in harmony in order to forget their rough pasts.

AUs
Halloween Humanoid AU- A gang of misfit monsters hostilely live together. The entire universe is happening in a mentally insane bird's mind. The bird (which has black and red eyes, stitches all over, and a dragon wing replacing one of her wings) uses puppets to deal with the deaths of her friends.

Horror AU- c̸̡͘o̡͟m͜͜i̶n̵̡g͏̕͞ s̷ò̸o҉͘͘n͜͠

Dawn Universe-

Known Characters in this Universe: Dawn, Twilight, Summer, Riptide, Rustle, Star, Ash, Andromeda, Evan, Jinx, Nova, Barracuda, Alberta, (more assorted winged wolves)

(SPOILER-FREE SUMMARY) A winged wolf named Dawn lives in the Hawk Pack. The Dawn stories pretty much sum up her adventures.

AUs
Furry AU- (POSSIBLE SPOILERS???) Dawn, a winged wolf furry, goes to Hawk High School with her best friends. One day, she meets a mysterious stranger: a black, dragon-winged wolf furry who seems a little too... familiar.

Creepy AU- (DEFINITE SPOILERS) Mostly the same plot as the original Dawn universe, but the winged wolves that are killed (specifically Ash, Barracuda, Heather, and Jupitor) are horribly disfigured ghosts who haunt your dreams.

Draga Universe-

Known Characters in this Universe: Windcharmer, Silvergust, Queen Igneaflare, Shimmerscale, Sassafras, Frostbite, Skyline, (more assorted dragons)

Five species of dragons (Flora, Chlora, Solara, Frostia, and Twila) live in harmony under the rule of the royal Spectra dragons. They defend their peaceful land from the evil "Dark" Dragons, who are under the rule of Queen Igneaflare.

Nyan Universe-

Known Characters in this Universe: Nyan, Kip, Paka, Uni, Jacuzzi, Inu, Tac, Harley, (more assorted "background characters")

Nyan, an imaginative pop-tart cat, goes to school with his two best friends, Kip and Paka. One day, a new student transfers to his school: a beautiful green unicorn called Uni. However, what Nyan doesn't know is that his newfound crush's pretty eyes hold some of the darkest secrets.

AUs

Reverse AU- Tac haunts Nyan, while Uni is a daydreamy, happy-go-lucky unicorn. Not much changes except for Nyan, Tac, Inu, and Uni swap roles. Uni and Inu are siblings in this AU, and pop-tart cats wear necklaces (like unicorns do in the original universe).

"Mood Swing" AU- Tac and Inu are positivity spirits. Nyan and Uni are angsty mythical creatures, ready for love, but terribly shy and introverted. Tac and Inu have to work together to get Nyan and Uni to speak to each other.

Creepy Nyan AU- As a form of eternal suffering, Inu transforms Uni, Nyan, Kip, and Paka into hideous monsters. However, in the process, she accidentally turns herself and Tac into deformed versions of themselves as well. All of the creatures escape into the forest to hide their disgusting shame. Uni is a living insecurity trapped in a centaur-like form, and is constantly in physical and emotional pain. Meanwhile, Nyan is a confused, three-eyed pop-tart cat, desperate to find his lover. 

Birdeh Universe-

Known Characters in this Universe: Birdeh, Aviary, (more assorted birdehs)

With a birdeh representing anything and everything, Birdeh and Aviary struggle to find where they fit into this wacky and wildly diverse world.

Combination Universes-

"Main 5" Universe- 

Known Characters in this Universe: Windcharmer, Celestia, Nyan, Uni, Birdeh 

The original squad! These five work for a positivity-spreading organization known as "Crest of the Stars".

Battle Universe- 

Known Characters in this Universe: 

Good Side:  Humanoids, Draga Dragons, (Most) Winged Wolves, (Most) Birdehs, Nyan, Uni, Celestia, (some Nyan characters)

Evil Side: Dark Dragons, Inu, Tac, Yami, Yami's Army, Rustle and his Gang, Silvergust, Queen Igneaflare, certain Birdehs

The sides of good and evil constantly fight over dominance through battles. (Battle forms are used in this AU.)