He had been able to do what few others could - survive a meeting with the dread linnorm and better still, been able to trade with him as well.

Thy worth, sweet friend, is far above my gifts,

an elegant solution

You could also keep a tennis ball and a frog, or a catapult and a frog, but not all three together. I know because I tried it. The frog got a bit squashed between the ball and the handle of the catty.