Audhumla is a primordial cow in the Norse creation story. Together with Ymir the ice giant, she was among the first living creatures that came to life in Ginnungagap. She feeds herself by licking ice crystals of Niflheim. In turn, she nourishes Ymir through the milk flowing from her udders.
We do not know the fate of Audhumla as it is never mentioned in ancient Norse sources. When Odin and his brothers killed Ymir, the amount of blood flowing from the giant’s body was sufficient to drown all giants.
We assume that she either drowned in the same flood, or that she ran out of ice crystals when the world was reshaped. Then again, we do not know the average lifespan of a primordial cow. It could be the case that she simply died of old age long before the flooding already.