Mutamods are RetroSpace's permanent body modifications: ten purchasable mutations that pair every benefit with a built-in cost. You buy them from Dr. Miriam's vending machine in Janitor's Haven with credits, upgrade them with genetic material through three levels, and — this is the part the game underlines — you can never take one back out. This guide lists all ten with their unlock locations and every effect that is actually documented, flags the three whose effects nobody has recorded anywhere, and gives a buying order that respects the one rule that matters: a Mutamod purchase is forever.
At a glance
Total: 10 Mutamods
Sold by: Dr. Miriam's Mutamod vending machine, Janitor's Haven
Costs: Credits to buy; genetic material to upgrade (Lv1–Lv3)
Active at once: 3, per current guides — you can swap which are active, but ownership is permanent
Reversible: No. There is no uninstall, refund or removal method
Effects documented: 7 of
10. The effects of Skunk Bomb, Octopus Heart and Brain Parasite are recorded nowhere
Achievement: Muta-Freak — own all 10 at Lv1 or higher
The short version
If you read nothing else:
Every purchase is permanent. Judge a Mutamod by its drawback first and its benefit second.
Credits are a finite pool — guides estimate roughly 6,000–7,000 in the whole game — and Mutamods compete for them with tech gadgets and supplies. Online per-item price lists are not reliably sourced; budget against the pool itself.
Buy information and survival first: Bat Hearing and Moth Light are the safest early purchases on record.
The three undocumented Mutamods go last. Nobody knows what Skunk Bomb, Octopus Heart or Brain Parasite do. Buy them when credits are spare, or when you are finishing Muta-Freak.
Four Mutamods live in the alternate-timeline Medical Section, and two more are timeline-exclusive finds. Do not leave them to the very end of a run.
1. How the Mutamod system works
All ten Mutamods are bought, not found. Nothing drops from an enemy and nothing sits in a locker: each mod appears on Dr. Miriam's machine once you reach the area listed for it below, and from then on it can be purchased at the Haven. The "location" in this guide is therefore an unlock location — where the mod joins the machine's stock — not a pickup spot.
The economy splits in two. Credits buy the mod itself. Genetic material upgrades it, from Lv1 to Lv3, and genes are the currency you harvest from corpses with the Gene Sucker — including, after a death, your own previous body. Upgrades matter beyond this page: the Abomination post-credit stinger, the game's rarest ending flourish, requires at least three different Mutamods raised to Lv3 in a single run.
Current guides report that three Mutamods can be active at once, and that you can change which three are active — treat the exact slot count as guide-sourced rather than officially documented, because no official source states it. What is documented, from the game's own store copy and the fan wiki alike, is the harder rule: owning a Mutamod is permanent. Active slots can rotate. Ownership cannot. Janitors' Patch #1 (October
7) also fixed a display bug in the machine's Lv2/Lv3 purchase prompts, so the upgrade path is fully usable.
Mutamods are also entirely optional. The game supports pure-tech builds, mixed builds, and a zero-Mutamod run — which even earns its own post-credit stinger (Space Disease). Buying nothing is a legitimate strategy; buying carelessly is the only wrong one.
2. All 10 Mutamods: locations and documented effects
Locations and effects below come from the current guide literature — principally one guide family, cross-checked against the fan wiki's system pages — so read the seven "documented" entries as well-attested rather than officially published. Where a drawback has never been recorded, the table says so.
Moth Light — Medical Section, alternate timeline — Heals you while you stand in bright light — You move more slowly while the healing runs
Rhino Body — Medical Section, alternate timeline — Stronger melee attacks — None documented
Skunk Bomb — Medical Section, alternate timeline — Undocumented — see below — Undocumented
Unicellular — Medical Section, alternate timeline — Creates a decoy double of you — None documented
Bat Hearing — Nexus Plaza / Train Station — Sonar sense: you perceive enemies through walls — Your vision is tinted a fleshy orange
Pig's Mouth — Engineering, lower level, near the Pigman — Eat corpses to restore health — You feed hunched over, exposed and vulnerable
Octopus Heart — Engineering, Marco's office — Undocumented — see below — Undocumented
Grasshopper Legs — Borealis Garden, the room at the Garden D/C entrance — Jump higher — None documented
Brain Parasite — Grand Station, the Police Station office — Undocumented — see below — Undocumented
Tentacle Hand — Borealis Garden, alternate timeline, second floor — Grows a tentacle arm; reviews describe grabbing and striking with it, but its exact mechanics are unverified — None documented
The alternate-timeline Medical cluster (4). Four mods unlock in the other timeline's Medical Section, reachable after the Hyper Drive jump at the end of your first Medical visit. Moth Light is the standout: multiple reviewers ran it as their mainstay, because Aurora 5 is a brightly lit station and passive healing is rare in this game. Rhino Body is a straight melee upgrade in a game whose early hours are wrench hours. Unicellular gives stealth and retreat play a decoy to spend enemy attention on. Skunk Bomb is the cluster's mystery — it is on the list, it is for sale, and no guide, wiki or review records what it does.
The early pair. Bat Hearing unlocks earliest of all — listed at Nexus Plaza, with the Train Station also named — and it is the easiest recommendation in this guide: knowing what is behind a wall is valuable in every build, and its only cost is a tint on your vision.
Engineering (2). Pig's Mouth turns the station's corpses into meals: real sustain, bought with real exposure, since you feed bent over and defenceless. Weigh it against the corpse economy — a corpse eaten is also a corpse you are not extracting genes or loot from in the same moment. Octopus Heart, waiting in Marco's office, is the second blank: location documented, effect recorded by nobody.
The gardens (2). Grasshopper Legs, in the entrance room to Garden D/C in Borealis Garden, is the clean mobility buy: higher jumps, no documented catch. Tentacle Hand hides on the second floor of the alternate-timeline Borealis Garden. Reviews confirm the tentacle arm exists and is used to grab and strike; anything more specific than that is currently unverified, so treat it as a late-game experiment.
Grand Station (1). Brain Parasite sits in the Police Station office in Grand Station — the third unknown. Guide documentation specifically warns that Brain Parasite and Tentacle Hand are timeline- and area-sensitive finds not to leave to the last moment; the warning is documented even though the parasite's effect is not.
3. The three unknowns, stated plainly
Skunk Bomb. Octopus Heart. Brain Parasite. Three of the ten Mutamods have no documented effect in any source we could find — not in the guide family that catalogued the other seven, not in the fan wiki, not in reviews. Their names hint (a gas attack? a second wind? a passenger with opinions?), and hints are all anyone has. This guide will not dress a guess up as a fact: if you buy one of these three today, you are buying a mystery, permanently, with a finite currency.
That is why they sit at the end of the buying order below. The day a reliable source documents them, this page will be updated — until then, "unknown" is the accurate entry, and a better answer than an invented one.
4. What to buy first: an order that respects forever
Bat Hearing — earliest unlock, useful in every build, and its drawback never gets you killed. The safest first purchase in the game.
Moth Light — the reviewers' mainstay. If your playstyle already lives in lit corridors and fights near lamps, it quietly deletes a large share of your healing costs.
Rhino Body or Unicellular — pick by playstyle: melee-forward runs take Rhino Body; stealth-leaning runs take the decoy.
Grasshopper Legs — mobility with no documented downside; buy it when you reach Borealis.
Pig's Mouth — strong sustain for aggressive runs that generate corpses; weaker value if you are gene-hungry and extracting from every body already.
Tentacle Hand — late, area-sensitive, and only loosely documented. Buy it as a curiosity with spare credits.
Skunk Bomb, Octopus Heart, Brain Parasite — last, in any order. Completion purchases, not build purchases.
Two budget rules sit underneath the order. First, higher difficulties raise prices while the credit supply stays finite — on 1999 and especially Russ Kurtell, a full set of Mutamods, gadgets and upgrades may not be affordable in a single run, so treat the completion sweep as a Normal-difficulty project. Second, Lv1 is enough for Muta-Freak: buy breadth first, and spend genes on upgrades only after all ten are owned — unless you are also chasing the Abomination stinger, which wants three mods at Lv3.
FAQ
Can I remove or refund a Mutamod? No. No source documents any removal method, and the game's own pitch calls the modifications irreversible. You can change which (reported) three are active; you cannot un-own one.
How many Mutamods can be active at once? Current guides report three active slots. The figure comes from guide documentation rather than an official source, but the ownership rule underneath it is certain: everything you buy is yours forever.
Do I need Mutamods to finish the game? No. They are optional systems — the game supports tech-only and zero-Mutamod runs, and the zero-Mutamod run is recognised by its own post-credit stinger.
What do Skunk Bomb, Octopus Heart and Brain Parasite do? Nobody has documented them — not their benefits, not their drawbacks. This guide lists their unlock locations and leaves the effect column honestly blank rather than inventing one.
Are Mutamods missable? Partially. Four unlock in the alternate-timeline Medical Section and others are area- or timeline-specific; guides warn against leaving Brain Parasite and Tentacle Hand to the last moment. Nothing says an unlocked mod vanishes from Dr. Miriam's machine, so the risk sits at the unlocking step.
Related guides
RetroSpace Beginner's Guide: Difficulty, Saving, Cloning and Your First Hours on Aurora 5
RetroSpace Death and Cloning Explained: Heal-O-Domes, Corpse Runs and Cloning Degenerations
RetroSpace: All 29 Achievements and the Road to 100%
RetroSpace Endings Explained: Both Endings and the 6 Post-Credit Stingers