Subterranean Stalker is the fifth stage in Shadow Cosmopolis.
The battle will start with a few Pigeon de Sables. After that, nothing else will spawn until the base is hit, where Brollows and more Pigeon de Sables will be spammed, along with a Mr. Mole and Tackey.
If you take a little longer, another Mr. Mole will spawn, with more Tackeys.
Note that Slime Cat is fairly good here if you hit the base with it; the resulting shockwave will instantly kill the first Brollows and Pigeon de Sables (assuming Slime Cat is level 30 or above.)
Lineup: Crazed Macho Cat, Eraser Cat, Crazed Wall Cat, Crazed Sexy Legs Cat & Macho Legs Cat (to activate the Legs For Days Cat Combo), King Dragon Cat, Jamiera Cat, Crazed Mythical Titan Cat, Holy Valkyrie Cat, Awakened Bahamut Cat
Begin the battle by spawning a Jamiera Cat. He should be able to hold off the Pigeon de Sables. When the base is hit, the Knockback King, the Push-Back Prince himself: Mr. Mole appears, WITH Brollows, Pigeon de Sables, AND Tackeys being spammed. As quickly as you can spam meatshields, Macho Legs, Crazed Sexy Legs, and the tanks (King Dragon, Jamiera, etc.). After some time, spawn Holy Valkyrie. After she dies, send out Awakened Bahamut once Mr. Mole has finished his attack animation. Bahamut will most likely die quickly, because of Mr. Mole. The enemies should get very close to the Cat Base, so expect your base to take a couple of hits. After some time, Mr. Mole will get knocked back. Just continue spamming your units until Holy Valkyrie is available again. Try to hold out some more, and the Brollows and Pigeon de Sables will stop spawning. Because Tackey and Mr. Mole are both long ranged, and there are no close range units, the level should stop being too hard. Even if one cat enter the enemies' "blind spot", they will slowly die.
Now all that's left is to destroy the Enemy Base! Onward to Victory!
Strategy 2 (Requires Divine Kai)
Divine Kai is amazing on this stage, as it resists Mr. Mole's knockbacks, is resistant to the Brollows and Pigeon de Sables, has massive HP, and also has moderate speed, compounded with explosive attack power. These combined make the perfect counter to this stage. Crazed Titan Cat is fast enough to easily get into the blindspot after D. Kai, and Octopus Cat blocks shockwaves, halving damage from Pigeon de Sables. Hacker outranges Mr. Mole and helps to take out the Pigeons, allowing Kai to advance easily. The only real strategy with these cats is to try not to spawn anything from the first row. This makes the stage ridiculously easy.
Note on both strategies: Octopus Cat, Seafarer Cat, and iCat will effectively render everything in this stage useless outside of Brollows and Dark Doges. This means that they are obscenely useful