It's called King of the Mountain.

It goes like this, one starts as the king of the mountain, and the next removes him somehow in order to become the king.

For example:

- "I found a mountain and became it's king, I'm the king of the mountain."

- "A lightning bolt fell in your head and you died, I climbed the mountain afterwards and became the king of the mountain.

- "I climbed up the mountain and kicked you out, I'm the king of the mountain."

And so on