Who was Yehoshua Bin Nun's father? Obviously his name was "Nun". Who was he exactly? What do we know about him (and from what sources)?
According to the Midrash recorded here (we don't have such an extant Midrash) there is an entire backstory:
Yehoshua's father lived in Jerusalem, and his wife was barren. After many prayers she finally became pregnant, but Yehoshua's father became upset when he was told from On High that his son would chop off his head. Yehoshua's mother, knowing this, hid the baby in a box and cast it in the river where it was swallowed by a great fish. The fish was then caught for the king's feast and the king found the crying baby inside. The king raised baby Yehoshua and eventually appointed him Chief Butcher. Yehoshua's father later sinned against the king of Egypt, so the king told Yehoshua to chop off his head and take his wife, children, and possessions, as was the law in those times. When Yehoshua drew near his mother to come upon her, the bed became filled with milk from her breasts and Yehoshua was about to kill her for witchcraft. His mother then remembered the words of her husband and told Yehoshua that this was the milk that she nursed him with, as she was his mother. She told him the whole story, and he got up from her since he also remembered the claim that he had been found in a fish, and he repented. Therefore he was called בן נון because he was found in a fish and נון in Aramaic means fish. (I.e. יהושע בן נון means Yehoshua the son of a fish.)
Note that referring to this legend, Professor Louis Ginzberg wrote:
There is no way of telling where Shapiro found the legend, and I have very little hope that at present anybody would be willing to undergo the trouble [of] examining the rather bulky transcripts of Shapiro. There can be, however, no doubt that it is not a very old source, as can be seen by the style and language, which indicate a rather late period.