Great, now giant eyeballs are flying around, attached to meat-flowers. Really makes you feel unwelcome here, yeah? Although... maybe that's the idea, maybe these are just parts of some macroscopic immune system...
Macrophages are generally ignorant to most individuals even when flown too close past it. However, damaging anything near it or itself, or grabbing hold onto the Mutagen bulb renders it hostile towards anyone or anything that hurts Rockwell or his creation as a whole.
Appearance
The Macrophage looks like a swarm of tiny summoners.
Color Scheme and Regions
This section displays the Macrophage's natural colors and regions. For demonstration, the regions below are colored red over an albino Macrophage. The colored squares shown underneath each region's description are the colors that the Macrophage will randomly spawn with to provide an overall range of its natural color scheme. Hover your cursor over a color to display its name and ID.
This information can be used to alter the Macrophage's regions by entering cheat SetTargetDinoColor <ColorRegion> <ColorID> in the cheat console. For instance, cheat SetTargetDinoColor 0 6 would color the Macrophage's "lower body" magenta.
Type in values of a wild creature to see on which stats it's emphasized. Green values on a high-level creature are very good for breeding. If you have already tamed your creature you can try to recover the breeding stats with an external tool.[1]
Macrophage
The stat-calculator does not work in the mobile-view, see here for alternatives: Apps
Note that after the creature is tamed it gets bonuses on some stats depending on the taming effectiveness. This makes it hard to retrieve the levels on a tamed creature, so this tool is only for wild ones, but gives a first impression, how well the stats are distributed.
Combat
This section describes how to fight against the Macrophage.
General
Macrophages can normally be ignored for the most part unless they became hostile (identified when it opens its eyes). Hurting just about anything, even breaking the plants, will cause it to become hostile.
Strategy
A survivor should use a torch in third person to dispatch Macrophages faster. If any survivor has access to a flamethrower it would be best to use it, because the flamethrower has the ability to take down multiple swarms at once. You can also use a campfire.
Weaponry
A torch will work wonders for one to two Macrophage swarms at a time, whilst a flamethrower can take out crowds of them with ease. A campfire will also work if you can get the Macrophages over it.
Dangers
Macrophages inflict minimal damage while slowly draining stamina until it’s depleted. While it may not sound dangerous, it can be. It all depends on whats around a survivor(s) when they are getting swarmed, potentially making escape impossible especially with its ability to disable both sprinting and Tek Sprint from Tek Leggings with every hit.
Weakness
Macrophages are vulnerable to incendiary (fire) weapons and ammo. Torches will be a new survivor's best friend, while flamethrowers will prove more effective when dealing with large crowds.
Another option, is to light a camp fire. They randomly die after being near a camp fire after 1–2 minutes.
They attack very similar to the Insect Swarm so use the same fighting strategy to take them on.
The main difference being is that they will always attack other than only attacking if the player is not in the water.
Lore
The Macrophage is another Creature designed by Rockwell to exist on the Genesis Ship.
HLN-A speculates that they are part of Rockwell’s immune system, some sort of over grown Lymphocyte
Due to their small size and frailer build, it is possible that the Macrophages are actually juvenile Summoners and swarm together because they require strength in numbers in order to successfully deter any intruders.
Region 0:
HLN-A
Mutagen bulb renders it hostile towards anyone or anything that hurts Rockwell or his creation as a whole.
Health
Stamina
Oxygen
Food
Weight
Melee Damage
Movement Speed
Torpidity
Tek Leggings with every hit.
Summoner can be seen. It is most likely a Macrophage.
Desert Titan Flock, 
Insect Swarm, and 
Parakeet Fish School
