ABOVE: Killing Floor 2's next seasonal event is revealed in a new trailer with the debut of The Matriarch.

The holiday season is once again upon us, and that means it's time for some extra special festivities Killing Floor 2. The Yuletide Horror update will introduce a new community map called Sanitarium and a new objective map called Biotics Lab, two free and two paid new weapons, and the return of "zesty" Christmas Zeds. But the big addition this year is Rachel Clamely, making her Killing Floor 2 debut as a tough new boss known as The Matriarch.

Clamely is the daughter of Kevin Clamely, the former CEO of Horzine, the company responsible for the outbreak of Zeds. After turning them loose on the world, Clamely mutated himself into the monstrous Patriarch. Rachel Clamely helped bring down two clones of the Patriarch in the original Killing Floor, but in KF2 she's followed in her father's footsteps as the hideous Matriarch, bearing a Plasma Cannon, a Tesla Blast, and ferocious melee attacks.

"The Matriarch is a multi-stage boss that builds on and combines previous mechanics from other bosses. That being said, the Matriarch has a unique few tricks of her own. The boss battle is built on 4 primary phases, each tied to the different states of her health bars, broken up by escalating waves of E.D.A.R.s enemies that are added into the fray as she enters a new phase," Tripwire explained.

"As a general rule of thumb in order to succeed in besting the Matriarch, you and your team need to stay moving, always keep a clear view of available cover, pick up on her warning cues for each attack, and make sure you can compartmentalize the E.D.A.R. spawns, not allowing them to distract you from her behavior."

It's obviously going to be a tough fight, but players who can take her down a sufficient (but not specified, sorry) number of times will earn a Dynamic Jaeger Weapon skin for the FN-FAL assault rifle.

Speaking of guns, this is the new hardware you can look forward to:

HRG Incision – Field Medic: A railgun that fires overcharged, highly-piercing bullets and darts. The bullets are capable of shocking Zeds and inducing the EMP effect on them. Darts heal other players for substantial amounts of health when targeting other players. When used on Zeds, these darts deal much more damage than standard darts and have the potential to knock down or stumble Zeds caught in their path.

– Field Medic: A railgun that fires overcharged, highly-piercing bullets and darts. The bullets are capable of shocking Zeds and inducing the EMP effect on them. Darts heal other players for substantial amounts of health when targeting other players. When used on Zeds, these darts deal much more damage than standard darts and have the potential to knock down or stumble Zeds caught in their path. Winterbites – Gunslinger: Fire large, nitrogen ice shards that explode on impact, dealing damage and applying the freeze affliction to any Zeds caught inside its radius.

– Gunslinger: Fire large, nitrogen ice shards that explode on impact, dealing damage and applying the freeze affliction to any Zeds caught inside its radius. Mosin Nagant – Sharpshooter: Five-shot, bolt-action, internal magazine-fed military rifle. This M91/30 allows a capable sharpshooter to fire at distant threats, stab at nearby threats, and block and parry damage from incoming threats. (This is a paid DLC weapon. This weapon can be shared amongst players with the weapon sharing system.)

– Sharpshooter: Five-shot, bolt-action, internal magazine-fed military rifle. This M91/30 allows a capable sharpshooter to fire at distant threats, stab at nearby threats, and block and parry damage from incoming threats. (This is a paid DLC weapon. This weapon can be shared amongst players with the weapon sharing system.) Riot Shield / Glock 18 – SWAT: A combination of the Riot Shield and Glock 18. The Riot Shield can mitigate most incoming, frontal damage only while a player is aiming down the sights. Its bash is capable of slamming into multiple Zeds crowding in front of you. The Glock 18 is a fully automatic pistol with two fire modes: single and automatic. (This is a paid DLC weapon. This weapon can be shared amongst players with the weapon sharing system.)

And because no holiday is complete without Gary Busey acting in a threatening manner, Badass Santa is back, too. Introduced last year, Badass Santa is a purchasable playable character voiced by Busey.

Fans who stick the trailer out to the end (and those of you going back to re-watch now that you've read this) will notice a stinger teasing that "a new destination awaits." Tripwire said that this is not related to Yuletide Horror, but a reference to a new map that will be revealed next year: "We just wanted to let our fans know that there's much more to come with Killing Floor 2 in 2020, so stay tuned."

Killing Floor 2: Yuletide Horror will go live on December 10 on Steam.