(I wanted to say ahead of time that when these first came out, they were referred to as "the dead PPS"/I think "DPPS." I'm sure they've since been renamed, but that's why I'm referring to them as this!)
I'm not sure if this is allowed, but I'd love to see the Dead PPS and two headed Deers from past Halloweens come back in events or Halloween. They could use either tame colors (like the husky colors in another of the PPS) or maybe more kooky/"out there" Halloween themes.
An example would be a Jekyll and Hyde type two headed deer, a zombie/pretty lady deer (one side is a zombie-fied female and the other side is the "alive" version), a groom and werewolf design, good twin and evil twin designs.
For the PPS lineart it could be in a Christmas and reuse the OG designs (coon litter, sun litter, moon litter, etc.) like other lines have had in the past. Another idea is the more tame colors as a nod to their original release. Such as a Dalmatian, solid black, solid white, chocolate colored, etc. (all in Halloween, like the originals).
I miss these lines so bad and wish they had more appearances than what they originally got. They could also be exclusive to Halloween like the chocolates/bonbon rats in Valentine's Day, the flower PPS bunnies in Easter, and the dressed up Dwarf hamsters in Halloween.
The lines I'm referring to:

(From Halloween 2014)

(From Halloween 2016)
(I'm not sure if these are specific-to-user lines like the Malks, but if it is, I get why they didn't come back)