Once the base is hit, a weak Those Guys spawns as a boss placeholder, alongside with another Pigge and Yakisoba U.F.O. Cat. Up to 4 Yakisoba U.F.O. Cats are spawned in this stage, each separated by a 300f ~ 400f interval. Those Guys will also be spawned more often, with another row spawning every 100 ~ 200f.
Similar to the previous level, meatshields and stacking up Gross Cats can deal down with the Yakisoba U.F.O. Cats. If you lose, focus on getting some of the more essential treasures in Empire of Cats and strengthening your army.