Mutagenic Wilds

Adds random mutations to Valheim's mobs that can combine and interact in unique ways, along with the systems that go with them.

Most creatures (not bosses, minibosses or tames) can spawn with special traits, and the rarest can stack several at once. Mutations combine into new names, can be passed on by breeding, and are recorded in the Mutation Compendium.

Note: The mod is currently in early access 0.9.3. Content is subject to change and bugs are expected. Join our Discord to stay updated with the mod's development.

Installation instructions

Recommended:
Install Mutagenic Wilds through Vortex mod manager or r2modman/Thunderstore mod manager.

Manual install:
Install BepInEx for Valheim. Place the Mutagenic Wilds files in your Valheim BepInEx/plugins folder. Launch the game once to generate the config. For multiplayer, make sure the server and every player use the same mod version.

Mutations

Creatures roll Mutations when they spawn: 30% in every biome, then a 20% chance of each extra mutation. Combinations create new names, and five mutations on one creature makes an Exodia.

The number of mutations is gated by current biome and by boss progress to not feel oppressive in the early game. Bosses, mini-bosses and traders are left alone by default. Player summons only gain Size Mutations.

Everything is editable. Spawn chances, weights, sizes, damage numbers, colours, names, loot and recipes can all be changed in the config, and any mutation can be switched off. (As the mod develops there may be less niche cfg options available).

There are over 20 Mutations, each with an accompanied Glyph for visibility:

• Tiny, Small, Large, Giant (Size): Tiny 60%, Small 80%, Large 125%, Giant 150%. Bigger creatures are tougher, hit harder and move slower. Smaller creatures are the reverse. They are generally more common than other mutations, allowing for more visual diversity among Valheim's creatures.
• Relentless: Never drops its target, endlessly chasing until either one is dead.
• Undying: When killed turns into a harmless blob, then revives if you don't finish it off.
• Moronic: Only attacks its own faction. Buuut its victims ignore it. It never fights you, so it drops less.
• Vampiric: With three variants. A regular Vampiric heals for 75% of damage dealt but starts burning alive when exposed to the sun. An Elder Vampiric heals more, and is immune to the sun. And the super rare Ancient Vampire, explained below.
• All-consuming: It will seek out & eat other creatures, gaining some of their health and damage, up to 3 stacks.
• Elemental: Its attacks apply Elemental debuffs, including Fire, Frost, Lightning, Poison and Spirit, with matching colours. Its auras and blasts apply the element's debuff. Fire Elementals visibly burn, and warm nearby players just like a fire should. Unique mechanics when combined with other Mutations. (Not many right now, more to be added).
• Golden: Super rare. Acts normally until you spot it, then runs away and vanishes two minutes later. Kill it for coins and gems, with increasing rewards by biome.
• Shedding: Passive animals only. Drops passive loot like eggs, hide or feathers every few minutes.
• Alpha: Passive animals only. Hurt it and members of its herd come to its aid, one after another. When it dies the herd backs down.
• Glass Cannon: Has 1 HP, but is incredibly lethal. It cannot kill you from full health, and does less damage in meadows and forest.
• Friendly: Never fights. Its other mutations do no damage because they're just nice like that :)
• Mannequin: Stands completely still as 'decoration'. Adds comfort nearby and lets you sleep with enemies around. Same damage rules as Friendly.
• Rabid: A normally peaceful animal will instead hunt players (deer, hares, hens).
• Diplomat: Peaceful until something nearby is hurt, then focuses whoever dealt damage first.
• Mimic: Self explanatory; disguises itself as a chest until you open it or attack it.
• Drenching: Creates a mist around itself that leaves nearby targets Wet. Interacts with Elemental.
• Volatile: Stores damage, then explodes 5 seconds after first being hit, dealing at most half of anyone's health.
• Radiating: Emits a damaging aura that pulses outward.
• Mother: Spawns with a calf, and can produce more offspring.
• Impregnator: Its hits give you and other creatures Pregnancy stacks, up to 5 and at most one per hit. After a delay, a stack is consumed and a copy of the Impregnator spawns as offspring, minus the Impregnator mutation itself.

Young and Aged

Groups of three or more can contain a Young (small, grows up over time) or an Aged (permanently small).
Both can also carry mutations.

Vampiric Lineage

A 1-in-1000 roll on any mob, once Bonemass has been defeated. They gain +25% size, 5x health, 3x damage. Any hit that would kill it, leaves it on 1 hp, and only Allblack can finish it.

• An Elder Vampiric (the sun-immune kind) drops Allblack Blood.
• Smelt it like you would Silver to get Allblack.
• Craft Allblack Arrows, Bolts, a Sword or a Spear to bring them down.

Allblack also has its own damage type that deals bonus damage to any Vampiric creature.

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Mutation Compendium

A craftable book that explains & records every mutation you meet, with search and sorting. Craft it at a workbench (Wood 10x, Deer Hide 4x, Leather Scraps 8x). Default hotkey K to open it. Gamepad controls for the Compendium are supported but not yet fully tested.

Breeding and companions

• Impregnator: When damaged by one, a Pregnancy stack is given as a debuff. 2 stacks of pregnancy creates the 'nausea' debuff, causing you to vomit a random food item. Stacks add up, one birth per cycle. Dying or logging out gives birth to one stack at once and loses the rest. Offspring inherit its mutations.
• New meads & potions: 'Mead Base: Morning After' ferments into 'Childfree Potions' that removes nausea, and prevents gaining further stacks. 'Mead Base: Pillow Talk' ferments into 'Freyja's Frenzy' that doubles the pregnancy stacks cap, removes nausea, and massively increases the speed that offspring spawn.
• Tamed animals: Offspring combine both parents' mutations (never more than four total - you can't breed an exodia).
• Loyal companions: An impregnator offspring born to a player can roll Friendly. If it succeeds a further roll, that creature now belongs to you. Press E to toggle Follow / Stay. Two Loyals of one kind can breed, and they will fight for/protect you like regular tames.
• Kin Slayer: An Iron butcher's knife that kills Loyals (only their owner's) and mutated tames in one blow.

Compatibility

Requires the latest version of Bepinex and Valheim, updated for 1.0.16.

Support is being added for compatibility with other mods. Currently supported are:

• Equipment & Quick Slots (3.0+), the Compendium gets its own equipment slot and K opens it.
• Epic Loot, its drops follow the mutation loot multiplier and bounty creatures never mutate.

Localisation and translations are planned to be added.

Multiplayer & Config

Requires the latest version of Bepinex and Valheim, updated for 1.0.16.
Install on the server AND every player, on the same major.minor version, or the connection is refused. The server's config applies to everyone.

Configuration is editable in any BepInEx mod manager or by navigating to BepInEx/config/peachyyy.trophyidols.cfg.

Commands available:

Press F5 and type devcommands first.

mm_list                        list mutations
mm_spawn Boar giant,volatile   spawn with chosen mutations
mm_scan 60                     list mutated creatures nearby
mm_stats                       what the mod is holding right now (for a bug report)
mm_clear                       remove wild creatures nearby
mm_book open                   open the Compendium
mm_book give                   gain the Compendium in your inventory

Feedback & Support

The mod is in a Beta state. It has not been played through a full game (meadows > Deep North) yet, so some balance will be off. It will be adjusted in future updates, and your feedback is very welcome. Join our Discord community where you can report bugs or suggest balance changes.

Shoutouts

• Big thanks to my close friends for the sick ideas and helping out so much with the project!
• IronGate, for making Valheim.
• All the people making great mods on Nexus and Thunderstore <3

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Made by Peachyyy, with help coding from Claude.

My other mod, Trophy Idols, allows you to convert Trophies into Battle & Protection Idols for the Forge of Potential.

Mutagenic Wilds may carry an "AI generated" tag - but despite that a lot of human time, testing and care went into it. If you enjoy the mod, feel free to buy me some caffeine.