Ug is an enemy ghost encountered in Luigi's Mansion 3.  Ug also serves as a  supporting antagonist. Ug is a brute caveman ghost that resides on the Unnatural History Museum located on the ninth floor of the hotel. He serves as the ninth boss of the game, making his home inside the Tyrannosaurus Rex exhibit. His prisoner is a blue mushroom retainer. This Mushroom Retainer has the Basement 2 floor's elevator button in his possession.

Physical Appearance

During his first few phases, Ug manifests as a Tyrannosaurus Rex. His second form appears after his first few phases: a yellow-skinned, fat humanoid. His hair is very short. His weapon is a club that lets him cause a huge shockwave.


Luigi finds Blue Toad inside the main room of the museum upon making his way in and tries to release him from the portrait. However, Ug, now manifesting as a T-Rex's reanimated skeleton, comes up behind his back, attacks him, eats the whole portrait and hides it inside his skeleton, so Luigi has to destroy him. However, Ug is revealed to be just some other ghost.

At the end of the game, it is revealed that most ghosts in the hotel were brainwashed by King Boo, and thus were unwillling accomplices. Thus, this might also be true for Ug. However, his eventual fate remains unknown.


Phases 1 through 3

Luigi has to fight Ug's T-Rex form by throwing him artificial dinosaur eggs that will become stuck in his mouth before he swallows them. This makes the T-Rex reveal his core, and Luigi has to throw another egg at it, causing damage to the boss. Ug will try to cause some rocks from the ceiling to fall on Luigi. When Luigi hits the T-Rex for the second time, which requires the use of Gooigi to distract him since he only drops one egg at a time, Ug uses his strength to finally break free from his restraints and goes on his way around the room to kill Luigi. Gooigi can be summoned to take care of the dinosaur by using the rest of the fossils that the T-Rex destroyed to throw them at it. After damaging it enough, the T-Rex will finally collapse and be destroyed, at which point Ug reveals his true form.

Final Phase

After revealing himself as the one possessing it the whole time, Ug acts angry with Luigi for destroying the T-Rex and prepares to battle him with his massive bone that uses as club. Ug will swing his bone to harm Luigi and even charge and slam at the floor, creating an energy wave that damages everything and everyone on the ground. In order to defeat Ug, Luigi has to flash Ug at the right moment when he gets his club stuck to the ground, which allows Luigi to vacuum him. After getting defeated, Ug will throw his club in the air and humorously have the club land on his still-exposed head before the device sucks him in. After Blue Toad is released, he reveals having the elevator button to Basement 2, where Chief Mechanic Clem resides.


Luigi's Mansion 3 – T-Rex and Ug Boss Fight (Floor 9)
Boss - Ug - Luigi's Mansion 3 Music Extended


  • Ug is the second boss in the game to possess something. He does this during his first three phases by possessing the T-Rex skeleton statue. 
  • Though his real name is Ug, in the Dutch translation of the game he is literally called T-Rex.
  • He somehow resembles Marvel's superhero Hulk given his short hair, green skin and massive strength.


           Luigi's Mansion Logo.png Villains

Luigi's Mansion
Boos | Ghosts
Portrait Ghosts
Biff Atlas | Bogmire | Boolossus | Chauncey | Clockwork Soldiers | Floating Whirlindas | Henry and Orville | Jarvis | King Boo | Lydia | Melody Pianissima | Miss Petunia | Mr. Luggs | Nana | Neville | Shivers | Sir Weston | Slim Bankshot | Spooky | Sue Pea | Uncle Grimmly | Vincent Van Gore

Luigi's Mansion: Dark Moon
Big Boo | Poltergeist | The Three Sisters
Grouchy Possessor | Harsh Possessor | Overset Possessor | Shrewd Possessor | Tough Possessor
Beetle Whisperer | Bomb Brother | Creeper Launcher | Primordial Goo | Terrible Teleporter | The Brain

Luigi's Mansion 3
Amadeus Wolfgeist | Captain Fishook | Chambrea | Chef Soulfflé | Clem | DJ Phantasmagloria | Dr. Potter | Hellen Gravely | Johnny Deepend | Ghostzilla | King MacFrights | Kruller | Nikki, Lindsey & Ginny | Polterkitty | Serpci | Steward | Ug

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