This year we made it happen, and it was glorious!
We gained some inspiration from https://themonsterproject.org/ and made wonderful works of art like this happen:
A class of first grade students at one of my feeder schools, were instructed to draw monsters. There was little to no direction, just their own creativity! The art teacher then brought their monsters to me and students in both of my 7th grade classes were assigned a first graders monster.
We had a brief discussion about uninhibited creativity and how little kids have developing fine motor skills. We talked about shading techniques with colored pencils, the importance of coloring neatly, and how our monsters were a re-make of the originals. Then I set them free!
This project was an easy way to collaborate across grade levels and I am very impressed with not only the first graders original monsters, but also with my own students remakes of them!