Yes it is possible.
If you have the three layers before you make them separate here is what you do:
1. add a new transparent layer.
2. add the image on the position you want it on your layer. duplicate the layer twice.
3. put each of the three new layers so that there are one of them on top of each snow layer.
example:
christmas image layer
snow layer
christmas image layer
snow layer
christmas image layer
snow layer
4. merge each christmas image layer into the snow layer under it.
5. now just make each layer an image themselves and save them as GIFs.
just use UnFreez after that.
@TopHATslash: I'll put Alvin back in at another time. I'm sticking with my holiday sig and avatar for now. I'll then use my new years sig and avatar after christmas and then a new sig and avatar I made after new years. I'll go back to the alvin sig and avatar after that. I also have my normal sig and avatar.