a few days ago i saw someone selling regen luporas, you can regenerate colors and traits on them, i also found some regen puffadores while exploring the lineage of one

how are regen pets created? what happened to the pets that made them regen-able

Regen pets are pets that were created before a revamp and had, at the time, problematic traits (eather they were changed of slot, split in multipes traits or had masive changes done to them). In those cases the traits are wiped out and turned in trait points that the owner can place back the way they want (as long as the trait selected are dating from before the revamp), in the older revamps only the traits were activated as dye was widely avalable but most revamp are now also including the colorations.

also see: guide to regeneration and revamps