Here's a little stamp with a 3D figure of Eggman on top. This looks like it could be a 'self-inking' stamp. What does it stamp? The leaping Eggman stock art, and Eggman's name. You can see the outline of what it will make in the bottom of the lid. The Eggman on the top is not in this pose, he seems to just be standing. And since Eggy is here...you know that this had to be a part of a set with at least 1 other character on it.