Heres a tip- if u go into the bosses arena and forcetame it.... you'll be stuck there forever bc the boss gotta die in order for u to leave. :) hit de good button so more peeps can see

Okay. Hear me out. I defeated this on Gamma with 14 rexes, 1 yuty, and 1 daeodon.

The rexes had health between 9k-12k, with melee between 400%-600%. I didn’t have the daeodon doing health, and I didn’t have the yuty doing courage roar.

I only lost 2 Rexes!!!

That just proves how easy this boss is. Up this if you are like me.

For this fight, you will need 19 rexes and one yutyrannus. Portal is situated at the Blue Obelisk Terminal

Artifact of the Brute: 530010

Basiliosaurus and scuba gear needed.

Follow the path to the left every turn, till you end up in a big water chamber with the artifact in the middle

Artifact of the Pack: 685560

Crossbow, grappling hooks, bug repellent, weapons (best place to find megalanias)

Stick to the left every time in the cave, until you approach a small drop with xp book at it. Always stick to the right after that.

Artifact of the Devourer: 140863

Tamed Barryonx, possibly scuba gear, weapons

Follow the path, until you have to go underwater. Swim to the left in the water, then to the right. You will then be led to a massive ravine cavern, with glowing blue crystals on the walls. The artifact is right below you on the very bottom floor. You literally cannot miss it because it is glowing a bright purple.

5 Tribute Items:

Spino sail

Therizino claws

Megalania toxin

Megalodon tooth

Thylacoleo hook claws

Once at the arena, BE CAREFULL AS HELL THAT YOU AND YOUR TAMES DO NOT, NOT, NOT FALL INTO THE HOLE AT THE RIGHT. YOU AND YOUR TAMES WILL DIE IF THEY FALL IN, OR YOU DO.  Quicky get all your dinos in the fighting arena, as the boss has knock back damage. Fight at beta difficulty.

Make sure that you move your Rexs or creatures into the trees when you get teleported into the arena. This is to prevent your tames from falling into the hole in the arena, because if they fall they just die, and you lose the saddles and everything. Then you can go up on your yuty or whatever you are riding and you lead the Megapithicus to your tames, then let them go ham on the monkey. The Megapithicus is a glass cannon and anything g with a good saddle and a high health stat can easily destroy it. Just make sure that nothing falls into the death hole and you’ll be fine to actually fight the boss.

For those who are struggling with dossier popping-out (ASA, PS5). When almost dead, click all tames on passive, finish it off with your dino, when defeated do not harvest it’s corpse, ride off your tame and boom, your dossier is here for ya!

Not sure how well they’re gonna work with other bosses as I did megapithecus before broodmother, and ofc this is very reliant on what map you’re on but I did it with 19 shadowmanes and a pig (my dumb self had too many manes and my yuty got left behind) and it was a breeze. Shadowmanes get a pack buff and thornmail poison, they’re amazing in fights. Possibly better than rexes?

The megapithecus has two attacks a direct hit attack and a ranged Boulder attack. The boulder attack can and will kill you off your tame and I figured this out the hard way.so safest thing is to wistle attack Target hope off and have someone roar the Yuri good luck survivors.

For gamma:

12 rex 20k hp 300 melee

Beta :

14 rex 25hp 500 melee 1 yuty

Alpha :

18 rex 25 hp 500 melee 1 yuty 1 health pig

U dont need good saddles trust me the different between primitive and ascendant saddles only 10% damage resistance

To kill him safely you need an Assault Rifle/Pumpa Shotgun/Tech Rifle to be able to maintain your distance when shooting. How to maintain distance is quite easy, you only need to run from one corner of the arena to another and avoid stone throwing attacks.

conclusion: position your character in the corner of the arena while shooting if he is close then run to the other corner of the arena then do this repeatedly

Been said to be one of the easiest but yuti and rexs is all you will need. This boss on hard takes us about 4 mins. Surround and start chomping. Debuff with yuti plus buff your rexs.