Monsters
Vampires
Vampires are fast and strong fighters, but they have two big weaknesses: sunlight and water. If vampires step over blood, they will drink it to gain health. You can quickly de-escalate a fight with vampires by using a Blood potion and turning vamp yourself.
Grunt: One of the lowliest enemies in the game, but fast.
Devourer: Teleports to and immediately drinks blood to heal.
Hawker: Functions as a shop and is not aggressive (in previous versions, Hawkers had the same aggro mechanics as other vampires).
Brawler: Lumbering vampires that can throw you one tile.
Knight: A vampire with very high resistances which is most easily killed by sunlight.
Noble: A high level vampire that will go out of its way to move to blood tiles in the middle of combat to heal.
Humans
Humans are fairly slow and weak, but they cast powerful magic. Like most enemies, humans cannot see in the dark. Drinking a Soul Elixir around humans will instantly make them friendly to you.
Mercenary: The weakest human opponent. Casts one of the following Level 1 spells: FIRESTORM, ICE or SHOCK.
Marauder: A stronger and more durable version of the Mercenary. Casts the same Level 1 spells, but with a higher cast rate than Mercenaries.
Hunter: A mid level human that casts ENRAGE.
Artificer: The only human that can become aggressive against human players (if you attack their golems). They can create golems and buff them.
Solomonar: A dangerous wizard who casts Level 3 spells. They always know the Glow spell, but also one of the following (which is denoted by their robe color): FIRESTORM, ICE, SHOCK, or HEAL.
Golems
Golems are extremely slow, but heavy hitting. Being held together by magical electricity, all golems are healed by the ELECTRIC type. But they are also the only monster type vulnerable to BLAST damage. Golems do not bleed.
Lapis Golem: A basic golem made of lapis lazuli that can prove to be deadly early on if underestimated.
Sunstone Golem: A golem composed of stone that emits sunlight. The radius of the sunlight repeatedly expands outwards and then resets.
Ice Golem: Attacks with ICE damage, which can slow you. Ice Golems have poor resistances against SUNLIGHT, WATER, and FIRE.
Electric Golem: Attacks with ELECTRIC damage and casts SHOCK.
Ruby Golem: A golem composed of ruby which is far stronger than all others.
Magma Golem: Attacks with FIRE and healed by FIRE. This high level golem leaves pools of lava in its path.
Plants & Fungi
These enemies are generally not threats, but they have a few tricks up their sleeves. They do not bleed.
Green Man: A half man, half plant. When hit by SUNLIGHT (which heals them) they grow much stronger. Green Men turn into Husks upon death from which a Red, Blue, or Green Toadstool grows.
Elder Green Man: A high level Green Man. Turns into a Death Husk upon death from which a Death Cap Toadstool grows.
Blue Toadstool: Toadstools only move at night, but they are always active. Blue ones cast a MIASMA that causes delusion.
Red Toadstool: Casts a MIASMA that causes confusion.
Yellow Toadstool: Casts a MIASMA that causes poison.
Death Cap Toadstool: Stronger than other Toadstools. Casts a MIASMA that causes heavy poison.
Beasts
The hotel is crawling with all sorts of hostile beasts. Many do POISON damage and most are good sources of blood.
Bat: Bats are more annoying than else. They flitter around you with weak, but fast attacks. Flying.
Toad: Toads jump around randomly and attack you with their tongue from 2 tiles away.
Poison Toad: A toad this is sometimes poisonous.
Wolf: Wolves are not particularly strong, but they usually travel in packs. Wolves are friendly to you when you have Lycanthropy.
Bee: Much like the bat, Bees can be hard to hit. They will try to poison you and if they do, they die immediately. Flying.
Killer Bee: A much more aggressive type of bee, but this one doesn't lose its stinger. Flying.
Baby Spider: On its own, a harmless little spider. Its poison can stun you, however.
Wolf Spider: A huge spider that explodes into Baby Spiders upon death.
Field Viper: Vipers are extremely fast and can sense your movements, even around corners. They do POISON damage.
Sand Viper: A deadlier version of the Field Viper.
Rat Soldier: One of the weakest enemies. A safe way to get blood for vampires.
Rat Assassin: A mid level enemy that also does POISON damage.
Eel: An aquatic enemy that casts SHOCK.
Crocodile: Crocodiles are huge monsters that are easy to escape from on land. Be careful around water though! They can drag you into water where they get a speed boost and you get a speed penalty.
Lava Croc: A variant of the ordinary crocodile that is immune to fire and will try to pull you into lava.
Shark: Sharks are very, very fast and dangerous if you meet them in water.
Monkey: Monkeys try to steal a potion and then hop away.
Tiger: Tigers will leap next to and attack the player simultaneously.
Polar Bear: Polar bears are fast in water and graceful on ice.
Yeti: A somewhat slow monster that throws snowballs.
Elephant: Elephants will trample the player, pushing them and dealing massive damage if the player is against a wall.
Miscellaneous
Goblin: Neither fast nor strong, Goblins are one of the least threatening enemies in the hotel.
Goblin Anarchists: They explode upon death or even randomly when next to you. Best killed from a distance.
Moroi: An extremely dangerous foe that darkens the area around it and performs PSYCHIC attacks from a distance. Flying.
Gorgon: Their GAZE turns you into stone, so they can BLAST you.
Skeleton: A small skeleton that is somewhat vulnerable to BLAST.
GreaterSkeleton: Turns into bones when destroyed, which will quickly respawn as a Skeleton.
Balaur: The fastest enemy around. If they catch you, you are very likely doomed, but luckily they can only see in darkness.
Prismatic Mass: Every attack is a random damage type. Flying.
Naiad: Water spirit that wields a deadly combo of TEMPEST and GLACIATE. Flying.
Gargoyle: A flying enemy that turns itself into stone.
Harpy: A fast enemy that will only fight you if other enemies are nearby.
Big Sludge: Sludges leave behind toxic sludge piles that explode into poison when stepped on. Big Sludges split when they have less than 2/3 hp.
Medium Sludge: Medium Sludges split when they have less than 2/3 hp.
Small Sludge: A weak sludge that cannot be split further.
Demons
Demons are the strongest regular enemies in the game. When they bleed, they bleed Demon Blood which heals vampires (even overhealing them) and grants them demonic abilities.
Imp: The weakest of the demons and the only one to be found outside of the underworld. Deals FIRE damage.
Demon Bat: A demonic version of an ordinary bat. They can drain health when attacking. Flying.
Demon Toad: A demonic version of an ordinary toad. Attacks with FIRE damage.
Demon Viper: A demonic viper whose attack causes poison, confusion, and delusion simultaneously.
Demon Ghoul: A demonic spirit who normally leaves you alone, but will attack when you're under full health. Deal PSYCHIC damage.
Steel Demon: This demon hits really hard and does not bleed.