Floor 39 is the thirty-ninth level in Heavenly Tower.
At about 10 seconds an Elder Sloth will spawn. Roughly 20 seconds later, the boss, Codename "Red Riding" comes out, followed immediately by a Mr. Mole. A few seconds later the first Tackey spawns, followed later by more Mr. Moles and Tackeys. Up to 4 Mr. Moles and up to 4 Tackeys each will spawn. After the final Tackey, no other enemies will spawn.
The key to this stage is speed. Bring units that are as fast as possible, to sneak through the blind spots of Red Riding, Tackey, and Mr. Mole. Manic Lion Cat is an extraordinary cat on this level, as well as Awakened Bahamut. Spawning Manic Lions as quickly as possible can overwhelm the Elder Sloth, leaving the rest of the enemies vulnerable to their own blind spots.
Remember to time your units well so Red Riding doesn't snipe them. Sniper the Cat can be very useful on this stage as he can control the distance of the enemies on the battlefield.
Easy Catellite strat:
Line 1: Two worker Cat level up Catcombos, or 2 attack up catcombos.
Line 2: Manic Lion Cat, Maglev Cat, Awakened Bahamut, Immortal Yukimura, Catellite.
Rush the Elder Sloth with Catellite. After ES dies, purely rush the enemy with all the line 2 units.
If you don't have these units, just use other rushers or tanky that resist knockback.
Strategy 2 (cheese): by Link9058
Items required: Sniper the Cat
Row 1: 2 cannon start level up M combo (if your cannon recharges fast enough already, then use speed up or damage up combos instead)
IMPORTANT: you MUST use the standard Cat Cannon for this trick to work.
The first thing to do is wait until you have 1700 cash, and at that exact time, turn Sniper the Cat off. Proceed to spawn a Manic Lion at 2000 cash to bait the Elder Sloth, spawning another one as soon as it's off cooldown. Fire the cat Cannon at 1800 cash, and turn Sniper the Cat back on at 2500 cash. If all is done correctly, the manic lion will have clipped through the Elder Sloth, and after Codename "Red Riding" exits the base, your Manic Lion should either be attacking either her, or both her and the base. Now just wait for the Manic Lion to destroy the base while you stall the elder sloth!
IMPORTANT: DO NOT fire the cat cannon after your Manic Lion clips through, as this will push the Mr. Moles back and make them kill your Lion. Using the Sniper is okay however, as it will only target Codename "Red Riding"
if you wish to finish the battle more quickly, try to kill the elder sloth using long range or tanky units. Once it dies, you can keep spawning manic lions and other rush units to help destroy the base. Use the sniper once Elder Sloth has died to knock Red Riding back and only Red Riding so that more lions can hit the base.
Strategy 3 (rush ft. Shadow Gao):
Powerups: Rich cat, speed up(optional)
Lineup row 1: Cool japan+extra cat of your choice (you can use sashimi cat for money+ M, or hayabusa for unit speed + M, or dps cat of your choice)
Lineup row 2: Manic Lion cat(30), maglev(40), l'il valk(35)(or some other dps 10k+), shadow gao(40), a.bahamut(40)
The point of this strategy is to kill the elder sloth as fast as possible, then kill the codename red riding before she can kill your base. If done fast enough, no ototo base enhancement is required, however, if levels are not high enough/tackey kills your a.bahamut too quickly, it may take longer. I had a level 18 base (survives 4 shots + 1).
Lure the elder sloth to your base. When it is close to your base, spawn a maglev. When it dies, spawn a manic lion and an a.bahamut immediately. When you have enough money, spawn l'il valk. DO NOT SPAWN ANYTHING ELSE UNTIL ELDER SLOTH IS KNOCKED BACK! IT IS A WASTE OF MONEY! When elder sloth is knocked back, start spawning all your dps cats(manic lion, maglev, and maybe your dps from row 1). When it dies, spawn shadow gao, and keep spamming your dps cats. If done right, money should not be a problem once your cats reach the red riding. When red riding dies, keep spamming until you destroy the base (the tackeys/mr.moles can be easily dealt with using manic lion and maglev), and spawn a.baha again when it reloads.