The level starts off with one Berserkory, accompanied by an occasional B.B. Bunny. After a while, two more Berserkorys spawn with the same amount of time between each spawn.
As there is no strong peon to support the Berserkories, you can easily defeat them by stacking anti-Red Cats with knockback or stop abilities. Just make sure to quickly kill each of them apart to avoid fighting several Bersekories at once - to assume this task, strong anti-Red units such as Crazed Fish Cat and Island Cat are recommended.
Alternatively, try bringing along the Gross! combo (Gross Cat, Crazed Gross Cat, Creepmallow), Apple Cat (Super Rare Cat), and Gentleman Bros. If you time it correctly, every enemy in the level will be permanently frozen by a stack of Gentleman Bros. and Face Cats, allowing you to kill them at your leisure.
Yet another way to cheese the stage is to bring Dread Pirate Catley along. Just spam him (maybe with some Recharge Speed Up combos), and with good initial RNG, the Berserkories will be unable to get close enough to attack.
Another cheese method is to spam iCat (True Form of Apple Cat). Beserkorys will have no chance of attacking as they will be frozen indefinitely.