New Boss - Rex Matriarch: Osseous

New Boss - Rex Matriarch: Osseous

New Boss : Osseous

  • Help out in the pursuit of Archaeological enlightenment and learn a little more about Anachronia
  • Take on this new mid level boss encounter featuring the Skeletal Matriarch Osseous!
  • Get your hands on a new Necromancy combat ring that synergizes with your necrosis abilities.

Welcome to Jurassic Park

The Rex Matriarchs were a triple threat of dangerous dinosaur dames that challenged you to branch out across each of the Combat styles. Now, you will need to flex those Necromancy skills as some bumbling archaeologists have unearthed the best kept secret on Anachronia.

Osseous, the tyrannical terror, the skeletal sovereign, the most dangerous pile of bones this side of Catherby... you get the picture. Complete a short quest and trek through the Rex Matriarchs lair into the bone laden ossuary - where you may have unwittingly (or wittingly) helped bring forth the fourth Rex Matriarch.

Bones? Smones. I am a master Necromancer

Your mastery over the undead will be needed to combat Osseous, as like the previous Matriarchs, she is highly resistant to all damage except Necromantic types. Better bring along the undead gang to help face this foe, or even bring some friends.

Osseous will challenge you with a variety of attacks from throwing ranged projectiles, to smashing you with its tail and even summoning minions to chomp on your ankles. You will need to use your abilities and movement to control the battlefield and strike down your foe.

For the seasoned boss hunter, Osseous will pose more of a challenge then the other Matriarchs - but remains more approachable than the biggest late game bosses. This boss is hoping to teach more mechanical combat skills around dealing with priority enemies, using your damage at the correct times and evading dangerous attacks.


Osseous will be following in the footsteps of the previous Matriarchs, but will also come with her own unique collection log separate from the others.

This log will include a brand new Necromancy combat ring that will enhance your ability to gain Necrosis stacks

A new Boss pet

A new title for completing the log called "the Skeletal"

And a spicy little extra - you can find Jail Cell Keys which can be used to free up to 3 different baby dino pets!

Free my boy, he ain't done nothing wrong.

Alongside these new rewards, all the standard drops from the original three Rex Matriarchs will also drop from Osseous too (although with with some tweaks).

History of the update

The three original Rex Matriarchs were released back in 2021, with the intention to make a trio of bosses that were a more challenging version of the Dagannoth Kings. The idea of adding a fourth matriarch is not a new one. For those players with a keen eye, you may have noticed this with a few hints scattered around the lair.

With the idea planted, Osseous' design was excavated in Game Jam by Mods Abe, Camel, Shrike, Fowl and Rain (with plenty of help from other Mods). Game Jam has always been a great opportunity to try out some design ideas and Osseous gave us the opportunity to flesh out a pre-existing area with something new, fun and rewarding.

With this project leaping from GameJam to a more active production, we've focused on respecting the original Rex Matriarchs design while continuing to incorporate Necromancy elements deeper into the world. We hope that this blending of the two feels as great to you as it does to us!

Osseous releases on May 28th (that's a Tuesday, as it's a Bank Holiday!)

- The RuneScape Team

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