well in that case
I've got two ideas, see if they fit your fancy.
1. Toys for Christmas~
- Grab a Pokemon, and make it look like a toy!
- e.g. substitute wheels for feet, apply shine, make sharp edges rounder, make it completely metallic, make it a wind-up toy, depict a child playing with it etc.
- No using Pokemon from the Mineral egg group (because they all look like toys already.)
2. Christmas Vacation!
- Grab a Pokemon, make it look like the tourist of a country!
- e.g. Emboar in Alaskan fur coat, Gardevoir in a kimono drinking Matcha, Golurk with an American flag and a rugby ball, Dunsparce dressed up for k-pop etc.