cow's legs up

From Michigan dairy farming. Refers to a dead cow that's buried on its back with its leg protruding out of the ground in order to minimize the size of the hole to be dug. Colloquial use refers to anything that is completely, absolutely dead with no hope whatsoever of it being saved or resurrected.

"Did you see that burning car. That thing is cow's legs up for sure!"

full moon and empty legs

In other words, "Bring it all in"

When there is a full out. Full moon and empty legs.

Liquid Leg Warmers

To be suffering from a particularly nasty bout of Diarrhea.

Tina was wearing the old Liquid Leg Warmers today, the bathroom was a mess!