南山大王 I Am the Southern Mountain King
那群妖扎下營盤，將一面錦繡花旗閃一閃，老怪持鐵杵，應聲高呼道：「那潑和尚，你認不得我？我乃南山大王，數百年放蕩於此。你唐僧已是我拿吃了，你敢如何？」那群妖扎下营盘，将一面锦绣花旗闪一闪，老怪持铁杵，应声高呼道：「那泼和尚，你认不得我？我乃南山大王，数百年放荡于此。你唐僧已是我拿吃了，你敢如何？」
逐句解 Line by line
The pack of fiends pitched camp, gave a flourish of a brocade flowered banner, and the old fiend, gripping his iron cudgel, answered the shout and called back loudly, "You wretched monk, do you not know me?
The fiend does the whole ceremony — camp, banner, weapon, formal challenge. 應聲, to answer a call, takes 應 as yìng, the responding reading rather than the modal one. In 認不得, cannot recognise, 得 is de, the hinge that marks whether somebody can or cannot manage a thing.
I am the Great King of the Southern Mountain, and I have run loose here for several hundred years.
放蕩 is to range about unrestrained, and he says it as a boast. Several hundred years sounds impressive until Wukong starts doing arithmetic with it, which is exactly what happens next.
Your Tang Monk I have taken and eaten already. What do you propose to do about it?"
The taunt is delivered as settled fact and it is a lie — the monk is tied to a tree in the back garden. 敢如何 is what-do-you-dare, the standard closing dare of a challenge speech.
The fiend's mistake is announcing a title. Wukong is a specialist in titles: he extorted one out of heaven, fought a war over it, and knows exactly what a name is worth and who is entitled to one.
Everything the fiend says here is designed to sound large. A banner, a mountain, several centuries, a meal already eaten. It is a performance of seniority, and it is about to be taken apart on precisely that ground.