A pogostick is a toy that children use to jump around on.
In the graphic novel The Adventures of Ook and Gluk: Kung-Fu Cavemen From The Future, the characters Ook Shadowski and Gluk Jones were shown to be on the same pogostick while escaping Mog-Mog, a tyrannosaurus rex. The two cave-children bounced over a ravine to safety.
Gluk's pogostick is a simple pogostick. It is most likely made of stone, with two horizontal areas on it: the handles and the place where one would stand on it. It also has some kind of spring on it, which can make it bounce very far, as it bounced both Ook and Gluk over what appeared to be a ravine several feet long.