I decided to do some jotting down of where every enemy is located at which dungeon and floor they reside on. I totally overlooked that there is an Armor and Weapon library in game for the longest time (Enter a dungeon>Menu>Info) that tells you of where gear that you have already found drops from. While this is true, the loot tables seem to remain constant and varied due to chests and Mimics. Mimics seem to have a far more diverse if not limitless loot table but the quality of loot is still bound by the level of the dungeon as well as your Luk and treasure Passives.
I figured out how to control which bosses will show up when you reach the end of a dungeon. Below I have a Lvl next to each boss, and that is the level of the dungeon that they first appear. Not only that but there are a certain number of different bosses per dungeon, so once you reach a certain dungeon level, the bosses will then cycle back through again. For example on the -Mountain- you have Bahamut Lvl. 18, Hydra Lvl. 19, and Goddragon Lvl. 20, so when you select dungeon level 21 you will get Bahamut, then 22 will be Hydra, and so on.

Here is the weapon and armor library and underneath is the dungeon enemy list, for a list of how each pet affects your stats and what skills they have, I suggest looking here.

Updated to version 1.0.4 for IOS

-Tutorial- 3 Floors

B1F=Babyslime
B2F=Babyslime
B3F=*Slime*

-First .D- 6 Floors

B1F=GreenslimeBug
B2F=GreenslimeBugHotstuff
B3F=BugHotstuffMegaslug
B4F=HotstuffMegaslugKillerbee
B5F=MegaslugKillerbeeMantis
B6F=*B.Gladiator*=Lvl. 1*Snailbug*=Lvl. 2

-Slimenest- 10 Floors

B1F=SlimeMagmaslime
B2F=SlimeMagmaslimeGreenslime
B3F=MagmaslimeGreenslimeWhiteslime
B4F=GreenslimeWhiteslimeMudslime
B5F=WhiteslimeMudslimeElecslime
B6F=MudslimeElecslimeBlackslime
B7F=ElecslimeBlackslimeAngelslime
B8F=BlackslimeAngelslimeBigslime
B9F=AngelslimeBigslimeEvilslime
B10F=*Slimeking*=Lvl. 1*Venomslime*=Lvl. 2

-Fort- 12 Floors

B1F=GoblinSpider
B2F=GoblinSpiderGoblinmage
B3F=SpiderGoblinmageGobknight
B4F=GoblinmageGobknightBat
B5F=GobknightBatGargoyle
B6F=BatGargoyleGobclown
B7F=GargoyleGobclownEyeguy
B8F=GobclownEyeguyDarkknight
B9F=EyeguyDarkknightGobhopper
B10F=DarkknightGobhopperDragon
B11F=GobhopperDragonBeserker
B12F=*Goblinlord*=Lvl. 4*Draco*=Lvl. 5*Guardian*=Lvl. 6*Bitedog*=Lvl. 7

-Haunted- 13 Floors

B1F=SkeletonGrimmy
B2F=SkeletonGrimmyLantern
B3F=GrimmyLanternZombie
B4F=LanternZombieGhost
B5F=ZombieGhostSnowgirl
B6F=GhostSnowgirlBrolly
B7F=SnowgirlBrollyPhantom
B8F=BrollyPhantomDarkeye
B9F=PhantomDarkeyeKappa
B10F=DarkeyeKappaSoulknight
B11F=KappaSoulknightLuminos
B12F=SoulknightLuminosWitch
B13F=*Balloongst*=Lvl. 8*Misty*=Lvl. 9*Rotgod*=Lvl. 10*Wight*=Lvl. 11*Frankie*=Lvl. 12

-Tower- 15 Floors

B1F=HellhareHarpie
B2F=HellhareHarpieOstrich
B3F=HarpieOstrichChimera
B4F=OstrichChimeraGiraffe
B5F=ChimeraGiraffeBluedevil
B6F=GiraffeBluedevilGoldknight
B7F=BluedevilGoldknightLionel
B8F=GoldknightLionelUnicorn
B9F=LionelUnicornFlyeye
B10F=UnicornFlyeyeChicknight
B11F=FlyeyeChicknightShocker
B12F=ChicknightShockerBalloon
B13F=ShockerBalloonWhitebird
B14F=BalloonWhitebirdSkydragon
B15F=*Dumbo*=Lvl. 12*Handsel*=Lvl. 13*Turtlos*=Lvl. 14*Horseman*=Lvl. 15

-Mountain- 16 Floors

B1F=MinibearGolem
B2F=MinibearGolemMonkey
B3F=GolemMonkeyLanddragon
B4F=MonkeyLanddragonT.Rex
B5F=LanddragonT.RexGameogre
B6F=T.RexGameogreSheldragon
B7F=GameogreSheldragonBigbear
B8F=SheldragonBigbearBulbeye
B9F=BigbearBulbeyeGriffon
B10F=BulbeyeGriffonMinotaur
B11F=GriffonMinotaurFirezard
B12F=MinotaurFirezardBonedragon
B13F=FirezardBonedragonBallbear
B14F=BonedragonBallbearTornado
B15F=BallbearTornadoLizardman
B16F=*Bahamut*=Lvl. 18*Hydra*=Lvl. 19*Goddragon*=Lvl. 20

-Mudcave- 20 Floors

B1F=MudslimeNeedlebug
B2F=MudslimeNeedlebugGolem
B3F=NeedlebugGolemAmmonite
B4F=GolemAmmoniteMuddy
B5F=AmmoniteMuddyDwarf
B6F=MuddyDwarfBamboon
B7F=DwarfBamboonBeetle
B8F=BamboonBeetlePonybear
B9F=BeetlePonybearPanicbird
B10F=PonybearPanicbirdPrimebear
B11F=PanicbirdPrimebearLicky
B12F=PrimebearLickyGnome
B13F=LickyGnomeBaal
B14F=GnomeBaalMummy
B15F=BaalMummyBulbeye
B16F=MummyBulbeyeRollman
B17F=BulbeyeRollmanDeathmage
B18F=RollmanDeathmageCentaur
B19F=DeathmageCentaurStonegolem
B20F=*Mudron*=Lvl. 24*Sandworm*=Lvl. 25*Kong*=Lvl. 26

-Forest- 20 Floors

B1F=ThornP.Shroom
B2F=ThornP.ShroomFlyrrel
B3F=P.ShroomFlyrrelThicklyleaf
B4F=FlyrrelThicklyleafTroll
B5F=ThicklyleafTrollTono
B6F=TrollTonoWitcher
B7F=TonoWitcherG.Shroom
B8F=WitcherG.ShroomFluffyleaf
B9F=G.ShroomFluffyleafPumpkin
B10F=FluffyleafPumpkinEatroot
B11F=PumpkinEatrootStumpy
B12F=EatrootStumpyReddevil
B13F=StumpyReddevilBrutalplant
B14F=ReddevilBrutalplantPokey
B15F=BrutalplantPokeyMudman
B16F=PokeyMudmanPakupaku
B17F=MudmanPakupakuMt.Golem
B18F=PakupakuMt.GolemVaseplant
B19F=Mt.GolemVaseplantP.Spider
B20F=*Serpent*=Lvl. 30*Cannibis*=Lvl. 31*Pokeking*=Lvl. 32

-Waterway- 20 Floors

B1F=WateryFlea
B2F=WateryFleaShellmet
B3F=FleaShellmetBubleslyme
B4F=ShellmetBubleslymeHermit
B5F=BubleslymeHermitSumoduck
B6F=HermitSumoduckBluelizard
B7F=SumoduckBluelizardJelly
B8F=BluelizardJellyMersoldier
B9F=JellyMersoldierMerman
B10F=MersoldierMermanUndine
B11F=MermanUndineTerrapin
B12F=UndineTerrapinWatergolem
B13F=TerrapinWatergolemDropeye
B14F=WatergolemDropeyeTallbat
B15F=DropeyeTallbatSquid
B16F=TallbatSquidMerdine
B17F=SquidMerdineLicky
B18F=MerdineLickyDartfish
B19F=LickyDartfishBigslime
B20F=*Bullwhale*=Lvl. 36*Octoblue*=Lvl. 37*Levioth*=Lvl. 38

-Factory- 20 Floors

B1F=ChimeraGoldknight
B2F=ChimeraGoldknightPrimebear
B3F=GoldkightPrimebearGaruda
B4F=PrimebearGarudaSheepman
B5F=GarudaSheepmanLuminos
B6F=SheepmanLuminosY.Dragon
B7F=LuminosY.DragonMersoldier
B8F=Y.DragonMersoldierDarkeye
B9F=MersoldierDarkeyeElecgolem
B10F=DarkeyeElecgolemGenie
B11F=ElecgolemGenieLionel
B12F=GenieLionelFlyeye
B13F=LionelFlyeyeT.Rex
B14F=FlyeyeT.RexCyclops
B15F=T.RexCyclopsBluedevil
B16F=CyclopsBluedevilShocker
B17F=BluedevilShockerChicknight
B18F=ShockerChicknightWyburn
B19F=ChicknightWyburnTornado
B20F=*Machine.A*=Lvl. 42*UFO*=Lvl. 43*Machine.B*=Lvl. 44

-Volcano- 20 Floors

B1F=LavaglobScorpion
B2F=LavaglobScorpionDragon
B3F=ScorpionDragonWhitecat
B4F=DragonWhitecatBeserker
B5F=WhitecatBeserkerHeateye
B6F=BeserkerHeateyeTrooper
B7F=HeateyeTrooperBlade
B8F=TrooperBladeEbifurai
B9F=BladeEbifuraiGascloud
B10F=EbifuraiGascloudMinotaur
B11F=GascloudMinotaurPhoenix
B12F=MinotaurPhoenixCyclops
B13F=PhoenixCyclopsFirezard
B14F=CyclopsFirezardGaruda
B15F=FirezardGarudaFiregolem
B16F=GarudaFiregolemHotstuff
B17F=FiregolemHotstuffLuminos
B18F=HotstuffLuminosPanicbird
B19F=LuminosPanicbirdDarkknight
B20F=*Behemoth*=Lvl. 48*Vulpus*=Lvl. 49*Volcanis*=Lvl. 50

-Lucifer.D- 30 Floors

B1F=EvilslimeB.Shroom
B2F=EvilslimeB.ShroomShadoweye
B3F=B.ShroomShadoweyeBlackcat
B4F=ShadoweyeBlackcatGameogre
B5F=BlackcatGameogreMr.Germs
B6F=GameogreMr.GermsMedusa
B7F=Mr.GermsMedusaAhriman
B8F=MedusaAhrimanSorcerer
B9F=AhrimanSorcererBlackbird
B10F=SorcererBlackbirdScorpion
B11F=BlackbirdScorpionGriffon
B12F=ScorpionGriffonBaal
B13F=GriffonBaalMask
B14F=BaalMaskBlade
B15F=MaskBladeBrutalplant
B16F=BladeBrutalplantMinidevil
B17F=BrutalplantMinidevilMerdine
B18F=MinidevilMerdineDeathmage
B19F=MerdineDeathmageSleepybear
B20F=DeathmageSleepybearTrooper
B21F=SleepbearTrooperLanddragon
B22F=TrooperLanddragonDaemon
B23F=LanddragonDaemonChimera
B24F=DaemonChimeraSoulknight
B25F=ChimeraSoulknightBigslime
B26F=SoulknightBigslimeDeath
B27F=BigslimeDeathLamia
B28F=DeathLamiaHellhound
B29F=LamiaHellhoundDevil
B30F=*Lucifer*