In one chapter, Sun Wukong and Zhu Bajie fight a giant python demon who swallows Sun Wukong. Who proceeds to "shape him" from inside like a bridge, then like a boat, then adds a "mast" (by stretching his staff in the middle of the serpent's back).
In one chapter, the local ruler doesn't like buddhists so he enslaves anyone that shaves their head like one. Wukong puts them all to sleep and uses insects that eat hair, thereby making everyone in the palace bald.
In one chapter, Wukong and his fellow disicples are stealing offerings from a taoist temple when the taoists come back. So they decide to pretend to be Lao Zi and other taoist immortals, and when they are beseeched for the Elixir of Life, Wukong gives them his piss.
When dealing with Lady Earth Flow, Wukong casually suggests that he'll rescue Xuanzhang by turning into a fly, sneaking into her belly, and tear her apart from the inside out. Xuanzhang is at first horrified by this, but changes his mind in a matter of sentences. At least one translation literally has him saying "Oh, well."