Can anyone explain this?

Likely it's a sedimentary rock that formed while it was under the ocean and then uplifted but it had a layer of another type of rock between it and the other sediments so if formed a ball and as it uplifted and wrote it away the other softer sediment washed out leaving this spherical shape That's just my guess

Moeraki boulders. Here are some pictures I took in NZ. Huge (up to 10ft), perfectly spherical calcite and clay buried boulders exposed by erosion to roll into the ocean from the hills nearby. Just breath taking stuff.

Saiyans spaceship

Not enough fiber.

It's called a concretion. They form naturally when calcite, iron oxide, silica and other materials form around a nucleus, such as a fossil or mineral crystal. They've been well understood for many years, and often a source of fossils.

yes....it is called Concretion

Zeus Threw that Ball at Hercules when he was mad at him, that is where it landed, Don't piss off the Gods.

Simple. It's a cannonball from a pirate spaceship. The ship utilizes materials from the environment it's occupying to craft ammo. By doing this: One- reduces weightload of the ship. Two- never run out of ammo. Three- more rum can be stashed aboard.

Marine sandstones often form ball shapes when there's something in the center that can leach out causing a spherical hardening pattern. Check the center for a gigantic crab!