Alright, I feel like the wiki is pretty outdated on the subject of mutation categories, so I thought I’d make my own guide. But I’ve only played a few mutation categories and I’ve played even fewer post threshold. So advice on the missing categories would be welcome, plus your own thoughts on the ones I’ve got.
Pre-threshold, Mycus is pretty tame. Marloss berries are a self-replicating and infinite food source. The cost is that you get a benign if annoying addiction and you can’t take mutagens, plus Marloss tends to scrub your other mutations.
Post-threshold Mycus is alright. You become slow and dependent on mycus fruits for your sustenance - you can’t drink water, so you have to eat fruits for that too. Metabolic Interchange is pretty much required so you don’t waste food. Anyway, you also become fireproof, immune to fungus, and fungal creatures are mostly friendly to you. You get an adrenaline boost in the presence of triffids. Mycus Sporogenesis is a powerful weapon, transforming hulks into soft fungal zombies and killing most other creatures, as well as creating friendly spores/fungaloids. Mycus Bloom can be used to fungify the area and also can be used to turn trees into marloss trees - a renewable source of mycus fruits. Overall, not powerful but has a few nice features and the only real downside is slowness.
Rat can pretty much survive off anything, at the cost of NPC interaction and some general downsides. They can also dig tunnels and don’t like the light. Some more detail would be nice.
Chimera is a high-maintenance combat machine. You have Eater of the Dead. It does exactly what it says. And you don’t need to boil water anymore. So you can literally just drink water out of a toilet like a dog.
Chimera also gives you the acid proof and acid blood that you can get from the slime. So your basically a badass killing machine with really easy maintenance requirements that might seem big, but are extremely easy to someone who knows what they are doing. Chimeras also don’t really need gloves, shoes, or hats. Because your going to be dealing so much damage from all your offensive mutations you will be killing them faster then they can get hits in.
The most glaring problem with Chimera is that he usually requires some serious luck or a shit ton of purifier to get right. Genetic Chaos can cause you to mutate two to three times a day. And change a lot about your character. They are also a hassle to keep happy. Hell I can see their pain. You can’t wear shoes; that fucking sucks…
Another problem is NPC interactions. They almost always either run away or just start shooting. And guns are still a problem with the Chimera. A couple good hits by a turret or NPC can take you out. But if your a Tailor Chimera you can fix that pretty easily. Like Kevlar-lined fur-wraps. Protection and warmth!
In conclusion: You smell like shit, look like some weird cat, lizard, goat thing with a club tail, and eat thirty times a day. But can clear entire cities in at least a week. What more do you want?
For an 8/8/8/8 survivor Alpha offers the best stat boosts out of all the post-threshold mutation trees with no appreciable drawbacks. Fast Metabolism won’t matter by the time you can make Alpha Mutagen with all the food you’ll have stockpiled, Nausea actually let’s you throw up on demand with no real drawback, and Weakening does literal scratch damage that sleeping regularly will have you not even notice. In exchange you get +7 ‘Prime’ versions of all four stats, which is equalvient to the ‘Insanely’ prefix most post-threshold mutants get for only one stat. You also get Good Hearing, Weak Scent, Pretty, Very Little Sleep and Robust Genetics along the way.
The only drawback is you don’t get any of the better extrasensory mutations like night or infrared vision. I’d recommend someone planning to go Alpha take some Troglobite mutagen first thing after you post-threshold. Ideally you’ll have gotten Robust Genetics either at char creation or due to shooting up for Alpha. Troglobite has some of the best pre-threshold mutations, several of which directly counter negative Alpha mutations and can give you both full night and infrared vision with minimal drawbacks. But it really isn’t worth going post-threshold with, so mutate and purify to your heart’s content because Troglobite mutagen only needs chunks of meat to make. Plus it has no stat changing mutations, so it won’t mess with your Prime mutations like most other trees.
Much higher stats than Alpha, but with worse decay and radioactivity. Also you get perfect night vision and you only have to sleep every few days. NPC relations are much improved, but if you don’t play with NPCs then it’s really only worth it for the night vision.
Annoying mutation tree that always seems to creep up when playing with unstable genetics. Gives you carnivore, light sensitive, cold-blooded, carnivore, slit nostrils, bad temper, carnivore, large talons, webbed hands, and carnivore.
Pretty much devoid of good mutations except for reptilian IR which is hard to keep as it conflicts with all eye mutations.
Also, no good post-thresh anything in it.
Water-themed lizard. Less bad crap, but doesn’t have IR. Has some good muts too, though.
Has only one post-thresh mut: insane dexterity. It didn’t even have that until recently.
Will limit worn slots to give worthless crap in return.
Post-thresh is notable for giving you proboscis which is infinite free food (can milk a single flower for infinite nutrition) in spring-autumn, but suffering (no eating, only drinking) in winter. Gives acid immune, though.
Literally nothing notable post-thresh. Incredibly mediocre, but has only one mutation that wrecks worn slots (paws).
Lupine but with Carnivore in category (as if lupine didn’t suck already). Also nothing notable in post-thresh.
Lupine but stronger, with more HP. Ponderous (walks slowly) and huge (WRECKS slots, doesn’t like to drive cars), but can gain some amazing strength and has neither Carnivore nor Fast Metabolism.
Like ursine, but with carnivore AND very fast metabolism in category, and nothing notable to make up for it.
Fast, but fragile and wrecks worn slots. Actually not a bad idea for a glass cannon, because you can outrun everything, niten stuff with insane perception and not get hit. Woodpecker beak is an incredible armor-piercing melee attack.
Post-thresh it has Gizzard, which cuts all nutrition gain by half, hummingbird beak which is a re-themed proboscis but you can still eat regular food. Also insane perception. Not sure if that perception is worth it.
Bird-lizard. Has IR, but like lizard, nothing really notable post-thresh. Just take bird, bird doesn’t suck (except when you get hummingbird beak, then it literally does).
Post-thresh intestinal fortitude “almost” lets you eat zombies (makes poison unlikely).
You are immune to every kind of side-effect harm - acid, disease, radiation, parasites, etc. all pass you by. Stats all become really high except strength, which falls really low. You are really weak to pain and some mutations will occasionally cause it, so keep painkillers handy. Every time you reach full hunger/thirst, you will split off to create a friendly little slimespring. You can’t carry much and you’re shit at fighting, but slime is hard to hit because of your dexterity and also you have regeneration. Acid blood brings instant karma to your foes. Also, you can just flow right through bars.
With Drunken Master or another INT-based martial art, you can deal pretty good damage.
Very high intelligence and dexterity, the ability to see in the dark, a good swimmer. Not bad in the melee because inflicts 9 attacks per round (default, beak-peck and 7x tentacle strikes(quite weak)).
There is ‘roomy shell’, but it’s absolutely useless garbage, because it provides tiny protection for a complete immobilization in return. You can shoot from one-handed weapons still.
The inability to put on armour - a complete mess. Even an ordinary zombie is able to cause significant damage, especially if they are many. To say nothing of the more powerful opponents.
Heat dependency is quite annoying as well.
Does not wreck slots. Will get rid of pain (totally) and give immunity to acid, but has all annoying mutations (schizo, mood swings, jittery, chemical imbalance) in category. Not a bad idea if you intend to get hit a lot.
Has very ponderous (really slow walking), huge (penalty for driving, can’t wear non-XL armor), horns and hooves in category, doesn’t have Ursine’s strength. Not good for crossing, not good at all. If you want to play cattle mutant, just play a vegan Ursine.
- it has conditional sleeping (like the plant variant) you have to make a thick web to be able to sleep, the pro is that you can make a thick web nest and and hide in it since it stops visibility (both from inside and out), but for some reason any mob has priority on destroying it
2.is fast and good at escaping, you can activate the web mutation and run, for some reason anyone following you gives priority to destroy the webs you leave (unless they are directly next to you)
- webs as you know are pretty flammable (so they are a pyro dream), you can activate them turn them on, and leave a trace of fire and destruction (and it burns buildings fast) so anyone following can be burned to death
The cons are you can get light sensitive and carnivore, if you get to full chitin mutations(armor, plate etc) you cant use any kind of head gear (unless is XL gear) you get torso and eye encumbrance, and said chitin can reduce DEX by 4 points.
Hates daylight and hates it hard, but will leave your slots and metabolism unwrecked. Good night vision and IR.
Saprovore and intestinal fortitude will let you eat rotten zombie flesh, a bit like rat.
-No more worrying about food and water
-Picks up Very Fast Healer
-Bark gives some damage resist
-No more diseases
-Up to 3x vine lashes in unarmed combat. Beat your enemies down like you’re the Whomping Willow.
-Ropes forever (meh)
-Deformed. You’re not pretty like the elves.
-Morale penalties for wearing anything that covers head or feet.
-Saprophage. Post-thresh you won’t need to eat anything, but Saprophage will make most “non-aged” foods unpleasant for you. Say goodbye to morale bonuses from cooking.
-You effectively lose the ability to sleep on anything but diggable terrain ie: dirt, grass, mounds.
-Sunlight Dependent. I managed to avoid it with robust genetics, purifier, and luck.
-You move slowly. Depending on how many ranks of Ponderous you mutate, you may move very slowly.
But remember, if you’re pre-thresh mutating, you can mix different mutation categories to get rid of poor mutations. Example: If you get Deteriorating, you can use Slime mutagen to get rid of it (Regeneration).