Sand, Stone

He was bored, sitting on the beach, looking out at the waves. So he picked up a rock and threw it out into the waves.

A moment later, a tenticle emerged from the choppy water, holding the rock. With a whip like motion, it threw the rock back, embedding in the wet sand with a small explosion of damp sand clumps.

The man was close enough to the impact to get hit by the flying sand, and so he got up and ran off.

And that's why the octopus waits in the bay, for the game of catch to continue.