so what old characters made an appearance so far?

[Demolisher]

Not counting Mumm-ra and the thundercats itself as that’s a no brainer

Lynx’o
Driller
Berbils
Spidera
Trollogs
Giantors
Slithe
Grune

Did I miss any?

[Tygra]

Snowmeow.

I can’t think of anyone else.