Battle of the Ox-Demon (决战牛大王; pinyin; Juézhàn niú dàwáng)was an area in Plants vs. Zombies: Journey to the West and later in Plants vs. Zombies: Great Wall Edition, and is the fifth area exclusive to the former's Adventure Mode.
This area was similar to Night as mushrooms are awake and no sun fell from the sky. Unlike Night however, the lawn required Flower Pots to be planted on, and the center four tiles of the second and fourth rows were unplantable, and began and ended with portals similar to the ones from Portal Combat (portals did not appear in levels 5-6, 5-7 and 5-8). The player also would start with three columns of preplanted Flower Pots and two columns of Sun-shrooms (except for 5-7, where the player would start with two columns of Flower Pots only and without any Sun-shrooms).
This area took place at different levels of Ox-Demon's Palace. During the final boss, the lawn had three phases; the first phase took place in the lower ground entrance of the palace where all of the previous levels took place, where the battle begins. The second phase took place on the middle level of the palace, where the battle took place after the Ox-Demon King Zombot was defeated for once. And the final phase took place on the top level of the palace, where the battle took place after the Ox-Demon Zombot was defeated for twice.
- This was the only area in Journey to the West that had different lawn designs for its boss.