Accessories. I'm on AI*Shoujo Better Repack 9.1 with no relevant custom additions. Some of them seem to be vanilla (though possibly DLC) if the order and preview background frame are anything to go by. YMMV regarding the translations, I did not change any translator settings from the defaults.
All in the Hips slot:
- "cat tail"
- "bunny tail"
- "demon tail" - very floppy!
- "bonito tail" - white/cream fox?
- "succubus tail" - firm, raised up and with a gold decoration. Arrowhead tip instead of the usual spade/heart for some reason
- "puppy" - short, fluffy, raised up by default, reddish
- "dragonic tail" - MASSIVE and ON FIRE!
- "taiku tail" - rounded, striped, raccoon?
- "reindeer tail" - tiny stub -last of the "possibly vanilla" options here-
- "[liliya]" - black&blue mecha
- "[rozaliya]" - white&pink mecha
- "Large Forces - Divine Ma<...>" - shiny succubus tail
- "[Liangpi]Neeko_weiba" - turquoise+purple lizard tail, see Neeko from LoL
- "[Liangpi]SpiritBlossom_Ahri" - blue fox tail, looks very "fake" like modern mobile/LoL graphics
- "Tail_1" - misoriented, actually a tail-shaped stream of fire
- "Au Ra Tail <1-4>" - untextured/monochrome lizard-like tails, which game are these from again?
- "Sting Trigger" - icon is a nun's veil for some reason. Actually a segmented metal tail very similar to Sasori's from Naruto but not identical
In the Head slot you'll also find a bunch of mecha parts such as cables, antennas or jets/lightsabres which might be used for mecha tails, some poorly sorted character-specific elements and just shy of half a million hair extensions which you can use as furry tails by changing their attachment point. There could also be a bunch of tongue/horn/wing/finger gadgets in other slots to use as lizard/monster tails but I didn't bother to go through everything.
Also search the Illusion (fan/modder/pirate) discord linked in the game threads. Discord is atrocious as a forum/repository but searching the mod and card/character channels for "lizard", "reptile" or "cat" might yield some additional results which aren't included in the pack.