Some great lines from the narrator in this one:
"Once they asked the wise man 'Is he who gives you a wild tiger in a jade box being truly generous?' The great sage replied 'How should I know?'"
"Truly it is said that dragon's feathers are as rare as sympathy for an expectant father. Never has a father been expectant in quite this way."
"Defeated, the god of fertility turned over a new leaf. This is why, today, very few men have babies."
I wonder if this is based on an original legend, because it plays like a messed-up fanfiction: Pigsy and Sandy both get pregnant from drinking the sacred water of a fertility god. Then Monkey has to obtain the antidote, reuniting two star-crossed lovers forced to be the god's slaves in the meantime.
There's a greatly amusing scene where Pigsy imagines himself fighting bandits with his child - a pig - on his back, in the style of Lone Wolf and Cub.