Make your very own robot. "Readymechs are free, flatpack toys for you to print and build. They are designed to fit on an 8.5"x11" page and printed with any printer. You’ll need double-sided tape, thick matte paper, and 10-15 minutes for build time."
These are great for older kids, a fun craft that almost anyone can do.
These would also look super cute lined up on a bookcase in an (older child's room). I say older child because some of them are a bit "grown up".
These can also be part "eco-friendly" if you use recycled paper or reuse paper that would have otherwise been thrown out.
Image by Readymech