Luigi’s Mansion 3 Dinosaur Boss (T-Rex Skeleton) Guide

Learn how to defeat the skeletal Dinosaur T-Rex in Luigi's Mansion 3 with the help of our guide to clear the 9F of the game

On Floor 9 – the Unnatural Museum – you will cross paths with the skeletal remains of a Tyrannosaurus Rex! This hulking creature of bone marrow and calcium will prove to be quite the terror, and poor Luigi’s going to need helping dealing with it. We have compiled this Luigi’s Mansion 3 Dinosaur boss guide just for that very purpose.

Luigi’s Mansion 3 Dinosaur Boss (T-Rex Skeleton)

You’ll be fighting it in an open area, you will be barred from exiting the area by purple fences. Above you there will be the skeletons of Pterodactyls holding eggs. The Dinosaur has only one weak spot: the glowing orb behind its rib cage. Attacking any spot other than that will do you no good. Follow the guide’s instructions and you’ll get through this with ne’er a scratch.

The first thing it will do is jump up and down, like a child throwing a tantrum. The impact will cause the Pterodactyl remains to drop the eggs they’re holding.

Use your vacuum to pick one egg up and fling it at its ribcage when its mouth is open. The egg will get lodged in its mouth, and it will attempt to remove it; his ribcage will be wide open while he’s doing so. Get the other egg and fling it at its ribcage.

This is where things get difficult. The Dinosaur, now quite livid, will destroy one of the Pterodactyl skeletons. Now in a bit of a frenzy, it has more attacks. He will continue to jump up and down, causing rubble to fall from the ceiling.

Just run from side to side, keeping a close eye on what’s above you. It will follow up with a deafening roar that’ll do more than just pierce your eardrums. The shockwave caused by his roar can be seen, so be mindful of it and get out of the way when you see it coming.


Now, like before, you need to lodge something in its mouth so you have the opportunity to shoot something at its ribcage. However, unlike before, you don’t have two eggs – you only have the one. You’re going to need the help of your double/clone. Have it stand before the Dinosaur, who will promptly eat him. While he’s busy chewing on our comrade, quickly grab the egg and fling it at its ribcage a second time.

Now, it’s even madder. It’ll break out of its enclosure and will begin chasing you around. More of the area is now open to you, so you have as much room as you need to run around. For the most part, everything is the same. It uses most of the attacks it’s used thus far.

However, he is now mobile and will be pursuing you nonstop. At certain points it will swipe its tail across the ground, doing 20 damage with that single hit. Try to keep yourself behind it or as far away from it as you can. If it gets too close, it’ll stomp on you and that’ll do considerable damage as well.

The strategy in beating is relatively the same. You’ll need to send the other Luigi to act as bait. Instead of eggs, you’ll have to pick up the bones of the other dinosaur exhibits. If your aim is true, you can hits its ribcage without the need of a decoy, although we don’t advise doing that.

Just use your double as bait/decoy, take aim and shoot at its ribcage. You’ll need to do it a few times, but rest assured that this tactic WILL work.

Now that you’ve taken care of the Dinosaur… time for the actual boss fight. That’s right, this is a 2-phase battle – the one you were after all along was a caveman who goes by the name Ug.

Ug will erupt out of the ground and will be wielding a massive bone as a club. He has a total of 400 HP and packs quite the punch. The one attack you need to be wary of most is his AOE attack. He flies up into the air, glows red, and brings his club down onto the ground – a shockwave sweeps across the area, doing tremendous damage and leaving Luigi in a staggered stage. However, this attack is also the only time when you can actually get a hit in.

Ug will be chasing you around, trying to hit you with his club. After a certain point, growing frustrated, he’ll do his AOE attack. Simply jump over the shockwave to avoid getting hit. Ug’s club will be lodged in the ground and it’ll take him a second to get it out. Get close to him and use your vacuum to suck him in and do as much damage as possible. Repeat the process until he’s out for the count!

A relatively easier battle as compared to the Dinosaur (T-Rex Skeleton and UG), but nevertheless, if you’re caught off-guard then you’re unlikely to get out of the skirmish alive. Be careful, be vigilant, and always be ready with a counterstrike.