I still kinda like my permanent pup/hatchling idea. ...XD; Also, I think it'd be nice to see the Frosted Leaflet evolve. But otherwise, actual new ideas...
A "game-themed" pet, maybe an Imeut or something? It has board game playing pieces around it, as well as a few cards. It represents getting together with your family to play games on holidays... I dunno about you, but that's what my family always does.
A puppet pet. It has strings attached to it, and its joints look like they have hinges in them. It's both a toy, and a reference to how, at least in America anyway, stop-motion animation and Christmas go hand-in-hand. Not just Rudolph and company, either--The Nightmare Before Christmas, too.
An "Angel Kitrell" that has a halo, silvery and gold colors, and things like that.
A Stargoyle with actual star patterning!
A Slikey/Slithey that's a dark brown-black molasses color. It's a Molasses Slithey!
A Snickey whose shell resembles a peppermint candy, with swirls and the like. And a soft pink body.
A Tundragoon that looks like a cookie! Instead of snowy spots, it's more of a tan color, and its spots resemble chocolate chips.
Shall I give more?