I've got a several in my collection, which I'll list in the order I imagine them to go in..

Tank Slayer
coop - One fast tank after another, but each one is stronger and hits harder than last. All temp health, health is awarded for damage. Difficulty based on flow length. Feels most like it's own game, certain maps have their own rhythms.

Tiny Terror
All very tiny commons (12"-24"). Kind of comedy relief, but people seem to like it. If we could reliably override models in modes/missions, I think it could actually be a "good" mutation, having mini-tanks and SI and being able to goomba stomp commons.

SI Plus
coop/versus mutation that tweaks infected. SI Can control commons, smoker cloud burns, spit and boom slow you down, jockeys move you faster, burning SI do more damage and bosses startle commons in radius.

The DAMNED Things
coop - A Fairly new one. All SI (except witch) are nearly invisible, only becoming more visible as they get very close or take damage.

Big Terror
Giant (and tough) Commons + Boomer. This one is only ok due to the bounding box on commons. Hits above waist don't register while standing. If we could specify override models/populations in modes/missions...

I have:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=129326766
A survival mutation that makes you constantly move around looking for weapons/items.

and
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=128428347
"coop", where survivors battle each other to get to the safe room first.




I've added support for both mutations and Holdout to Diescraper, and can set up support for other mutations if needed.
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=130389462

My turn:

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=128372457&searchtext=

Zombie Run is a versus mutation, where the survivors have to run through a deathrun-like course, in which the traps are the human-controlled special infected,

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=151788511&searchtext=

Biters is a solo mutation, where the common infected bite. When you get bitten, you start to bleed out and your blood buffs other zombies. I'm particularily proud of this one.

I'll post mine when I get back home. I'll be back at around 5 PM central time.

I have a couple to share:

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=152277381
Survivor Swap is a Co-op mutation and it does exactly as the title sounds. It swaps the survivor set around for official Campaigns.

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=130408814
United We Stand is a Survival mutation that's meant to be played on L4D2 Survivor Campaigns. The L4D1 Survivor bots spawn and assist you in trying to survive.

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=152433624
A Co-op mutation I created with help from my friend, giving ideas/suggestions and testing it. Only one of each weapon will be available, and only common Infected spawn. The Infected may be slow, but they pack a punch. Only headshots will kill the Infected. If you get incapacitated you'll be auto-revived, but an Infection timer will appear. You have 2 minutes to live until the Plague kills you.

I also recommend The Fish's Vampirism mutation:

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=127223178

[Deprecated post, new links somewhere below]

Guys - looks like we ran into some problems for today and will need to reschedule but we still plan on doing this before we release to everyone. I have gotten to play some of these already and they were amazing.

We will get some beta servers with these on them up in a few weeks and run the test then - I am thinking we should include everyone in the beta so they can see all the cool stuff you guys are creating - so please keep posting here and we will add them!

What about all the featured maps/campaigns, will the latest versions of these also be added to the servers?

How will this work? Consider an arbitrary mutation that is accepted into the l4d2 release build; will all L4D2 users be "subscribed" to the mutation? Or, will the mutation be "packaged" into the game? If the latter, how would the authors update/fix bugs? Thanks.

I wasn't 100% sure what to do, but I deleted my beta workshop files and moved them over to the public l4d2 workshop (new links below). Upon further testing, all three mods appear to be quite stable too. I've got another one in the works which I will release next week.

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=157525096

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=157524450

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=157523582

Thanks, Rayman for suggesting my Mutation :3

What ever happened to these plans?