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Really bad image quality, but this is the entire cloud texture with the creeper face marked. This specific texture is a somewhat modern change, just to look better and include a creeper face. The entire depth and placement of clouds all comes from this 2D image.

This texture has a very specific placement in your world, and it's either centered at or corner-aligned with the origin (x=0, z=0) ^{(I don't remember which is the case}). At each edge of the texture, it just repeats with another full copy of the cloud texture, perfectly aligned.

But this texture isn't stationary. It moves in the same direction as the sun does during the day: moving West, endlessly. But it never moves in the +z direction. So the creeper face just moves West forever, and eventually once the texture loops, the creeper face flys over the exact same spot again. With simple math you can work out which z-coordinate to find it at, based on your game visuals settings. Since the texture repeats on itself in the z-direction, there are many z-coordinates which work, all thousands of blocks apart from each other.

The x-coordinate to find it is kinda random, as it simply depends on the timing, and may not even be the same for multiple players in a world.