What exactly is this brain teaser? It seems that cucumber is not eggplant, but fell from upstairs. Who knows the specific topic?

This is a particularly fun brain teaser, and the correct answer is: the cucumber that hit his head. Generally speaking, what is normal thinking? According to normal thinking, cucumber is a vegetable, eggplant is also a vegetable, and cucumber is also a vegetable when it falls downstairs. Unless its head is smashed, it can't become anything else.