I love this idea. I would do it, get removable wall paper. - "A neighbour of mine has one wall in their house papered like this. Every time a new guest comes in, they are asked to colour-in a character and initial it.
Stamped upon a saturated ground of totally current colors, Turtle Bay's interpretive turtle design with hexagonal shell is both soothing and stimulating with its perfectly balanced scale. Featured here in from the Biscayne collection.