Carries crawlers into battle.

Mutalist Osprey is an infested Corpus Osprey that transports Crawlers and charges into players to unleash a toxic cloud.


  • Mutalist Ospreys will pick up and drop any type of Crawler, provided they are nearby. They can only carry one Crawler at a time.
    • They can carry even Nauseous Crawlers into battle, which can stun the player and leave them open to attack.
    • Mutalist Ospreys can also spawn already carrying Crawlers.
    • Killing the Mutalist Osprey first while carrying a Crawler will also kill the Crawler.
    • Destroying the Crawler first will allow the Mutalist Osprey to immediately target its nearest enemy before charging towards the target.
    • Crawlers being carried by Mutalist Ospreys are not alert. Unusually, provided that the Mutalist Osprey is within range of a melee attack, this allows players to kill the Crawlers being carried using stealth attacks or counterattack finishers. This will count towards stealth Affinity multipliers.
    • Avoid close quarter combat, since it will begin to charge and attack if you are close to them.
  • Mutalist Ospreys can charge at players in a similar fashion to Oxium Ospreys, during which they release a toxic gas trail along their path. Unlike Oxium Ospreys however, Mutalist Ospreys will not be killed if they make contact with their target.
    • They will only begin charging once the Crawler they were carrying has been dropped.
    • The gas cloud left behind will linger for 5 seconds, making the affected area hazardous to move in.
    • The cloud deals continuous DmgToxinSmall64.png Toxin damage to any player who enters it, bypassing their shields. The cloud can also inflict an 3-second DoT from a DmgToxinSmall64.png Toxin proc. So when a cloud is nearby, escape its radius as soon as possible.
    • As of Hotfix 13.8.3 (2014-06-20), Mutalist Osprey clouds possess visible toxin lines similar to that employed by Toxic Crawlers and Venomous Eximus, allowing players to detect them easily.


  • Mod TT 20px.png Vitality and/or Mod TT 20px.png Antitoxin mods are recommended to mitigate the damage dealt by the Mutalist Osprey's toxin cloud. The Mod TT 20px.png Rejuvenation Aura is also helpful in keeping all players' health regenerating to counteract the toxin's damage-over-time.
  • As the DmgToxinSmall64.png Toxin DoT scales sharply with level, it may be wise to outright equip Mod TT 20px.png Rapid Resilience instead of Antitoxin. Since a maxed level Rapid Resilience can shave off 6 seconds from the DoT, that damage will be avoided entirely.
  • Using LokiIcon272.png Loki's RadialDisarm130xDark.png Radial Disarm on these Ospreys can disable their poisonous charge.


  • While the main image of the Mutalist Osprey depicts its non-infested parts having aquamarine coloration similar to Shield Ospreys, it has orange coloration both in the Codex and in missions similar to Mine Ospreys. The way in which they drop Crawlers is also similar to Mine Ospreys dropping energy mines.
  • Crawlers that are spawned with the Mutalist Osprey have a reddish violet coloration, instead of their normal colors. This applies to all variants of Crawlers that are spawned. Crawlers that spawn by themselves and not by the Osprey have their proper colors however.
  • Mutalist Ospreys appear to be immune to status procs and can avoid DoT status effects, such as by DmgGasSmall64.png Gas or DmgToxinSmall64.png Toxin damage. The AoE gas proc effect will still damage them if they are in range, however, but they won't obtain the toxin proc.  
  • Mutalist Ospreys seem to be of the few infested affected by RadialDisarm130xDark.png Radial Disarm. It forces them to the ground like it does to Shield Ospreys, nullifying their ability to spray their toxin cloud.
  • Mutalist Ospreys appear to be immune to VaubanIcon272.png Vauban's Bastille130xDark.png Bastille, and can still activate their charge attack while being pulled into/held by Vortex, allowing them to escape.
  • NyxIcon272.png Nyx's MindControl130xDark.png Mind Control ability can target Mutalist Ospreys making the toxin clouds they leave behind for the duration of the ability damage enemies instead of players. However, if the Osprey is carrying a Crawler, the Mind Control 'status' will transfer to the Crawler once the Osprey drops it, leaving the Osprey as dangerous as before.
  • Specters are not affected by the toxin clouds.


  • Mutalist Osprey was first introduced in Update 13.8 (2014-06-19) for the Operation Breeding Grounds event.
  • They were shown as a prototype in Devstream 30.
  • They are the first flying Infested unit.
  • The Mutalist Osprey is divided by a non-infected and an infected side. But it seems that the Infested side is more dominant in controlling the Osprey and it is seen that the Mutalist Osprey works for the Infested only.
  • The word mutalist in its name may refer to Mutualism, which is a sector in biology which refers to how two different species interact with each other where each individual benefits. This refers to the Infestation taking over the Osprey, and taking the advantages while in fact, the Osprey is a Corpus production.


  • If you use ShadowsOfTheDead130xDark.png Shadows Of The Dead on an Osprey carrying a Nauseous Crawler, the Nauseous Crawler will spawn in a different color from other Shadows and lasts for an infinite duration. This Nauseous Crawler will be recognized as an enemy mob but cannot be killed by players (though it can still be killed by other enemies). If there are no more enemies on the map to defeat it, this can prevent the completion of Defense missions.
  • They often fly into textures and will throw their crawlers out of the map.
  • Unlike other enemies, they do not track invisible players. Instead, they will just idle in the air. This prevents new enemies from spawning.


Patch History[]

Update 28.0 (2020-06-11)

  • Fixed Mutalist Osprey Carrier’s ignoring Limbo’s Cataclysm bubble.

Update 13.8 (2014-06-19)

  • Introduced.

Last updated: Update 13.8 (2014-06-19)