Not much happens at the beginning of the stage. However, after a short lull, seven Iron Claw Xs will spawn in quick order! They will be supported by Doge Darks, Pigeon de Sables, and Metal Doges to act as meatshields.
At least four meatshields are needed to get in the way of the Iron Claw's single target attacks. Use Dragon Cat, Crazed Dragon, Drama Cats, Paris, and any other long-range attackers you have to chip away at the Iron Claw's health. An anti-black unit or two can be used take out the Doge Darks for easy money.
Strategy 2 by DonDonBeo: 8 meatshields and 2 long-range attackers
Line up : Li'l Macho Cat, Crazed Macho Cat, Mohawk Cat, Wall Cat, Crazed Wall Cat, Ramen Cat, Jiangshi Cat, Jamiera Cat, and 2 long-range attackers: Ururun Cat, The Peach Devils (recommend main attackers >410 range to out-range the Iron Claw).
Power-Ups: Rich Cat and Cat CPU.
At first , turn off the Cat CPU , spam Ramen Cat and some Wall to block and kill the Doge Darks. When you have enough money and The Iron Claws is near your base ( don't let them touch your base ) , turn on the Cat CPU and just see what 8 meatshields can do .