Juvenile Killer is the fifth stage in Squishy Cave.
4 Master A at a time will stack, respawning once one is killed. After a while, this limit increases.
Lineup: Wall Cat, Macho Cat, Sexy Legs Cat, Dragon Cat, Bahamut Cat, other ranged units.
Begin by sending out 1-3 Wall Cats, to save up cash. When the first Master A. comes out, begin meatshielding. These should be able to hold Master A. in place. Now begin spamming all ranged units, and send out Bahamut cat. Continue this, firing the cat cannon as soon as it loads. It may take a while, but it should work. Uber long range cats such as Assassinlan Pasilan or Hacker cat are also helpful. If needed, bring a third meat shield such as Boogie Cat.
Strategy 3 (Late-game Strategy)
This strategy only works if you are returning to this stage late-game on higher star ratings. Use Awakened Bahamut to deal gargantuan damage to the Master A.s before dying, and use Li'l Nyandam for constant support. This becomes even more difficult on Four Star, as you cannot use meatshields or Uber Rares like Aphrodite. In that case, fire the Cat Cannon before Awakened Bahamut reaches the Master A.s, similar to what you would do on Oncoming Storm, so he can get a hit in without dying. Eventually, the Master A.s will be pushed behind the base, and you can complete the level.