Killing these first four Crazed Fish should be easy and give you enough money to afford Crazed Bahamut Cat and UFO Cats. Afterwards, spam everything as you advance towards the enemy base. Don't worry about Super Metal Hippoe.
Crazed Fish Cat is a Super Rare Cat unlocked by completing the event stage The Crazed Fish appearing on the 21st of every month. True Form greatly increases his attack power and health. In The Battle Cats POP!, you can get him from the Rare Cat Capsule after completing Cosmic Club in Ch. 3 Interstellar Invasion.
Easiest was Crazed Fish Cat. Harder was Crazed Tank or Crazed Titan.
Crazed Tank Cat is another Tank Cat but with more versatility thanks to its notably increased movement speed. Just like Tank Cat, it can be spammed to halt the progression of the enemy frontline towards the cat base, making him an essential choice for nearly any level that requires meatshield spam.
At their current levels crazed cats are better but they are also faster. The speed is quite useful but you have more space between them.
This is a fairly simple yet challenging level; the best way to win is by not using meatshields at all but instead fight with only ranged attackers so a Crazed Gross doesn't hit a meatshield and trigger a Wave Attack.
Crazed Catgirl Yuki gains more health, damage, slow immunity and double movement speed. The stat improvements are very good, the health going up by 47% and the damage going up 25%, enough to make a difference in both of them.
This unit is great in Empire of Cats for clearing out Pigges and B.B.Bunnies, and in Stories of Legend for St. Pigge the 2nds but it loses use quickly due to high cost and low range. It is better to stack long ranged cats such as Gross Cat and Lizard Cat.
This cat can be useful in the early-game when most enemies have low range, allowing it to deal damage without getting killed. This is important, as his cost, health, and range quickly become his downfall once Empire of Cats is over.
Bronze Cat is a decent support unit against Metals. He can be very useful against tough Metal enemies like Metal Cyclone or Sir Metal Seal. He can also tank one or two hits from tougher Metal enemies. Overall, however, Clockwork Cat and Drumcorps Cat are still more reliable.
Crazed Bird Cat's range is quite serious, but the attack frequency and DPS are rather low, with only 2.1k DPS. Adding on, this enemy has a trait, which is Floating.
Crazed Bird Cat can be good when stacked with proper meatshielding. They can be used to attack enemies like Shadow Boxer K, Crazed Cow and Manic Lion, and other rather strong but short-ranged peons.
This cat has underwhelming stats outside of the very beginning of the game. Its use is, therefore, not recommended aside from an assortment of Cat Combos.
This cat is very helpful against enemies that are close ranged, as well. It can take some hits from waves, and its range is perfect against slow enemies like The Face.
Cheap and expendable, Boogie Cat can be summoned in masses to take hits in place of other, more important units. This meatshield role is quite valuable, if not for the wide selection of Cats able to perform this role much better due to faster speed.
Crazed Titan Cat has ridiculous amounts of health and attack power, and a dangerously high chance to create a wave. The wave length is level 7, so not even Hacker Cat can outrange it, making him rather useless.
Its effective is most noticeable on fast attackers with a low Crit rate like Catasaurus or Catornado. Her range is lower than Cheerleader Cat, but still high enough to outrange every single common Metal enemy, earning her a spot in any Anti-Metal lineup.
Like the original Axe Cat, Brainwashed Axe Cat suffers from its extreme cost efficiency issue, making it just as useless against Traitless enemies as traited ones.