My son turns 6 this year and this is what I came up with for his invite. I kept it a little basic because he invited his entire kindergarten class which meant I had to make like 50 invites. I used the Robot from the Robotz cartridge and the rectangle from George and Basic Shapes and welded them together on Design Studio.
For the layers, I only cut the mouth and stomach only and then added stickles at the joints, feet, hands and antenna. I added some google eyes and printed out the front and inside on my printer. Walla!