My Chowder Reanimated Scene 

Was fun to do. The full video is currently meant to come out December 25th if all goes accordingly. Go look at C_Reanimated on twitter for updates.
Thanks to fellow reanimate members Ositodraws for Chowder's pattern and @StradomyreArt for Mung's one.
For future reference, the unmoving plaid is done with the mask feature.
1. First you have your animation (coloured).
2. Then you copy it in its entirety onto a new layer, this layer you will remove everything except what you want replaced by the pattern so it will just be the coloured shapes of whatever is being replaced (in the instance of this video it was Chowder and Mung's clothes).
3. Underneath that have a new layer with your pattern where it will be underneath what you want it to fill. Make the copied layer a mask to go over the pattern layer. Then, with the original animation layer which should be above the other two, remove the colour so the masked pattern can come through.