Starfinder: Infectious Metamorph

Chris Van Deelen

Infectious Xenomorph (Humanoid Combatant) CR 5 XP 1,600


Neutral Evil medium Aberration

Init +3; Senses Darkvision 60 ft.; Perception +11


Defense                                                             HP 70

EAC 17; KAC 19

Fort +7; Ref +7; Will +6

Defensive Abilities Divide, regeneration;

Vulnerabilities Acid, fire and radiation, cold susceptibility



Speed 30 ft.

Melee Bite +14 (1d8+6) or one claw +14 (1d6+6) or both but at +10, or melee weapon +14

Ranged By weapon +11

Offensive Abilities: Infect, natural weapons



Str +2; Dex +3; Con +5; Int -2; Wis -2; Cha -2

Skills Athletics +11, bluff +16

Languages Common

Other Abilities Absorb, hive intellect, mimic

Gear One ranged weapon, basic armor (up to level 2)



Environment Any

Organization Solitary, small groups (1d4), medium groups (3d6), large groups (5d12)


Special Abilities

Absorb (Ex): The creature is able to use dead tissue to heal itself. As a full-round action, this creature can absorb the body – as long as it is organic, nothing inorganic will be absorbed - of any creature.  The body absorbed will heal a number of hit points equal to the creature’s original Constitution score.

Cold susceptibility (Ex): This creature can still be affected by cold-based attacks, but instead of killing the creature, it will slow it down and eventually cause it to go into a state of hibernation. Once the creature has sustained half its hit points from cold attacks, it will be staggered, allowing only one action per round. When it is reduced to a quarter of its hit points, the creature will only be able to move, and at half its normal movement rate. Finally when reduced to zero hit points, it will appear to be dead, although it is in fact alive, but in a state of hibernation. As long as it is kept below freezing, the creature will remain in this state indefinitely. Once temperatures are above freezing, the creature will regain 5 hit points per round until it is up to at least half its total, at which time it can finally move and act, but it is still staggered. This will remain as such until it has regained its full hit points, at which time it will no longer be considered staggered.

Divide (Ex): When the creature is under attack, particularly from Acid or Fire, it will often cause its body to split apart in order to ensure that even part of it can escape to continue the cycle of infection. This is considered a full round action and the creature will attempt to hide what it is doing. When this happens, the creature will be considered to be small size, and will have one quarter of the infected total hit points. It will then attempt to flee the area, using stealth – if possible, otherwise it will move at its maximum movement rate in order to escape.

Hive intellect (Ex): The creature, once it has begun to infect an area, has what is considered to be a hive intellect or mind. This allows a single creature to be able to control all other infected hosts as if they were one in the same, although it allows each host to retain its own memories and intelligence – after all, it needs to maintain the charade that nothing has happened.  Only those who have sprung from the original creature will work together however. If there are other infected, who came from a different host, they will often work against one another, even outright attacking each other, to ensure only one intelligence is in complete control.  They will automatically recognize one another as for what they really are, no roll is required.

Infect (Ex): The easiest way for the creature to infect a possible host is through physical interaction. Just touching the unprotected flesh of another creature (and it has to be skin-to-skin contact, as even simple clothing will block this). A Fort saving throw (DC 10) is required to avoid being infected by the creature. If the monster physically attacks another creature, such as clawing or biting, then the DC is dramatically altered. The DC becomes 10 plus whatever damage the creature inflicted, so if it bit a target, inflicting 11 points of damage, the DC becomes 21! Once the victim has been infected, they do not know what is happening to them. For simple skin contact, the infection will take 7-12 (6+1d6) hours to completely assimilate the victim. During this time if the victim is treated to any sort of cure disease or something similar, the infection will be destroyed and the victim will survive. The more damage a victim has endured, the quicker the assimilation will occur. If the victim has suffered 1-4 points of damage, then the assimilation time will be 1-6 hours. If the damage is 5-10 points, then assimilation will occur in 1-2 hours. 10 – 20 points of damage, 10d6 minutes, and finally if more than 20 points of damage has been inflicted, the assimilation will take only 1d10 rounds.  Once a victim has been assimilated, it is dead and becomes an NPC under control of the GM, although the GM is encouraged to take the player aside and inform them as to what happened, and have them continue to play, eventually changing and attacking other players to continue the cycle of infection and assimilation.

Mimic (Ex):  Having assimilated a new creature, the infectious Xenomorph will use the creatures memories and skills to maintain the illusion everything is alright. The creature automatically gains a +10 to Bluff checks as a result, but it can make mistakes. Also there are other ways of detecting the infection – medical scans, detect evil, detect aberration and the like will reveal something is horribly wrong. Usually when this happens, the creature will then reveal itself and go on a rampage to kill and infect all targets near it. The creature can use all the skills and equipment possessed by the host, but unless in dire straits, will change its body to use natural weapons in order to infect.

Natural Weapons (Ex): as a move action, the creature can cause parts of its body to change, growing claws, teeth, or whatever is required, in order to gain a natural attack. It can create one natural attack per round, based on the overall CR. For every 4 CR, the creature will have an additional natural attack, so a CR 1-4 will have one attack, 5-8 will have two, 9-12 will have three and so on.

Regeneration (Ex): The very nature of the creature allows it to heal rapidly from any wound not inflicted by acid, fire or radiation. The creature will heal 5 points of damage per round and can only be destroyed by using acid, fire or radiation.

Vulnerabilities (Ex): The species is very susceptible to acid, fire and radiation.  Whenever it encounters it encounters acid or fire, the creature automatically takes double damage. Furthermore the creature suffers -4 to any saving throw involving these particular types of attacks.


A particularly insidious and deadly alien life-form, this creature reproduces, colonizes and conquers entire worlds by spreading through the population via cellular infection. All that is required to start the process is the creature needs to get as little as a single cell of its own matter into a host, which then quickly begins to assimilate the host’s cells, metamorphosing the cells into that of the creature.

It is unclear why so few of these creatures have been encountered over time, as due to their method of reproduction and colonization should mean they could have taken over the known galaxy in a matter of a few years.

One theory has it other species, such as the Hunters and Engineers actively seek out and destroy any infestations encountered, typically by wiping the infested biosphere clean with nuclear weapons, fire and heavy doses of radiation. This would be one possible explanation as to why explorers across known space have encountered worlds wiped clean in such a manner.  There is also the fact the creatures are incapable of assimilating the Xenomorphs, as the acid the creatures use for blood is extremely deadly to this species.

Another theory is these creatures are hostile towards one another. Colonies created by one of the creatures will fight other colonies over possible hosts and resources, and this has been speculated due to the fact they do not work together when encountered, unless it is to simply subdue and assimilate any available hosts.

One aspect of the monstrous species which has baffled the few scientists, which have encountered them, is the fact even a single cell can infect and turn another creature. The puzzling aspect is the newly infected creature now has the knowledge of the infectious Xenomorph, and can use it to its advantage. So if the creature is stuck in a remote location, with only a few hosts available to it, it can infect the hosts and then use whatever technology and resources are available for it to construct vessels, even starships in order to escape and find fresh prey to turn into hosts.

The species seems to live to colonize and acquire technology, specifically anything which can be used to help them travel amongst the stars. They do not care for other life, except when it comes to using it as hosts. They are not interested in talking or negotiating, although once they have taken over a host, they are able to use all its memories, knowledge and skills. This can allow the creature to remain undetected for long periods of time before it finally reveals itself – typically when it is cornered or when it is ready to infect another host.

Often when it infects a host, so much damage is inflicted the host is killed. When this happens, the creature will take the corpse of the victim and carefully hide it away, until the assimilation has taken place.

The species is patient in some manners, not so in others. And it is thoroughly evil, relishing in spreading terror and mistrust among those whom it seeks to turn into more of its own kind. It is even willing to sacrifice hosts it has infected – as long as there are others who have been turned, in order to achieve its goals.

The creatures instantly know one another and will continue the charade, as long as it is in their best interest to do so. When at least half the population of an area has been assimilated, the creatures will drop all pretense of the hosts original form and will attack all at once, ensuring the complete destruction of a population and gaining control of the area to continue spreading.

Infection can be as simple as touching another creature with its bare skin, which means assimilation can take hours or longer, to attacking the possible host outright, inflicting as much physical damage as possible, ensuring a great deal of cellular matter will enter the hosts body, greatly accelerating the assimilation process.

If there is one thing the species is terrified of, it’s fire. Well, you can add acid and radiation to this equation as well, as all three will quickly destroy the creature. The problem is when dealing with fire, the creature must be turned to ash, or even if a few cells remain intact, they can easily infect another being and cause the metamorphosis to begin anew. Acid and radiation are the best methods of destroying an infection, as both will utterly destroy the life-form.

It should be noted once assimilation has taken place, the victim typically violently transforms as the creature asserts full control over the body. This leads to torn or destroyed clothing and equipment, which the creature will replace, disposing of the damaged garments to keep the charade going.


Infectious Xenomorph Template Graft (CR 3+)

After successfully infecting a creature, it becomes a new Infectious Xenomorph with the following rules.

                Required creature Type: Any

                Required Array: Any

                Traits: Absorb, cold susceptibility, divide, hive intellect, infect, mimic, natural weapons, regeneration, vulnerabilities  

                Rules: The infected creature retains all its skills, abilities, statistics and so forth, but gains the above traits and becomes an NPC under control of the GM (or in special cases, continued control of the player to maintain mistrust and terror).

Starfinder Creature Index

Chris Van Deelen is the creator and contributor to over half of the Wisdom from the Wastelands series, contributor to the Swords of Kos: Hekaton anthology. He also wrote Creatures of the Tropical Wastelands, and 100 Oddities found in a Car. As prolific as he is, Chris Van Deelen continues to write and produce material which will be in publication soon. Not only is he a prolific content creator, he also has a wide selection of fiction and stories! If you like his work, please follow his personal author page on Facebook and on Twitter to keep up with his latest news and game content.