Hybrids, the following pets are marked as hybrids, but are either only first generation, or have first generation versions, first generation source listed for reference.
Darkwalker Interactive housing item Gilded Skeleton Walmart 20 gift card Glacier Dragon drop in game Jade Oni drop in game Life Minotaur drop in game Lifedactyl crowns shop Maelstorm Oni chest from fishing Royal Armored Skeleton Walmart 20 gift card Sabertooth Level 98 Balance School pet Sandman Ghulture's Hoard Pack Skeletal Gladiator Walmart 20 gift card Wendingo There is a first generation in the hatchmaking kiosk, but no one knows the source, please double check that this first generation actually exists
The following pets are Hybrids, but not marked as such, there are no first generation versions of these pets that are known, pet mix to produce them is included for reference.
Pet:Frontier Dragoon Pioneer Dragon x any pet Pet:Playful Seal Pup Cunning Seal Pup x Intrepid Seal Pup Pet:Rain Beetle Storm Beetle x any pet Pet:Stormwarden Ice Colossus x Stormzilla
Frostzilla should be listed as a first generation, it is no longer available in game, but people actually have it and there is at least 1 in the Kiosk.
The hybrid frostzilla is merely a duplicate as it has the same body type and card as the first generation.
Just to update, I did receive a 1st generation Stormwarden from housing tours, never knew this existed as a 1st generation pet, so that one is correct.
