Are Awesome, and I don't mind BUT - non standard...?

from the sky? had a few

yup.

Every now and again I am guessing other stuff falls too but how do you miss a mammoth....lol

Miss a mammoth?How can you??They're freakin' huge. I get them every now and then. I almost feel bad they die on impact...maybe they have weak knees.That'd explain why giants guard them?

On the contrary, this is a standard feature in the game.
Been present since release.

I had a horse take off like a rocket once as well....rider and all. They never landed.....
All of this with V sync enabled for the curious.

LOL @ this.

i have seen a falling hagraven when i first exit the mines at karthwasten Village. I seen a giant FLYING up into the air in whiterun.
So yea, skyrim is definitely a fun world~

and try killing a mammoth on master mode at lv 10 below. You could not miss, but it takes freaking long time to kill. Even novice is about a few twenty hits.
Avoid them mammoths ><

You've to understand Skyrim physics. Mammoth are heavy, very heavy thus they sink into the ground. But Skyrim is a fantasy world where below ground there is an empty grey space so everything that clips through the terrain will keep falling in the void till they reach the edge of the cell coordinate system. But don't fear! Anything that pops out of the border will be respawned at 0,0,0 location (which is usually high above the ground).

Thus in an ironic turn of events, something destined to fall in the void for eternity is saved and put back in the game world, only to be destined to fall down to its premature death. Sheogorath couldn't have conceived a better plan himself!

Clipping problem>Falling out the cell boundaries>Respawned at 0,0,0>Fatal fall to the ground.

I wonder if this is caused (partially?) by overrendering or too high FPS as well? I've noticed that limiting fps from 120 down to below 85 stops some of the weird physics behaviors and animal distortions/displacements but I've yet to see if I'll meet flying animals again.

60hz Monitor with Vsync enabled so I doubt that was the case for me.