Who ruled Babylon when King Nebuchadnezzar ate grass with the cows?

According to Conservapedia, a Christian fundamentalist encyclopedia, "In 570 BC, Nebuchadnezzar, having completed his wars of conquest, returned to Babylon to concentrate on making it his showcase. At this time he dreamed of a tree destined to be cut down. Daniel tried to tell him that Nebuchadnezzar himself was that tree, but the king did not listen. Very soon thereafter, Nebuchadnezzar came to suffer the delusion that he was an animal, and to eat grass." This disease, known as Lycanthropy, involves a delusion that the affected person can or has transformed into an animal or that he or she is an animal. Michael Nisbett (2007) says a fragmentary cuneiform inscription in which an anonymous court official, possibly the king's own physician, could possibly testify to symptoms of depression in Nebuchadnezzar and therefore perhaps this depressive disorder.