The Brood are a fictional race of evil extraterrestrial insect-like beings that has appeared in many Marvel Comics. They first appeared in Uncanny X-Men #155.

Created by writer Chris Claremont and artist Dave Cockrum they were inspired by the xenomorphs in the movie Alien, a fact Claremont has publicly admitted. The Brood are parasitic and must steal the bodies of others to reproduce, and are used as one of the most insidious alien menaces in the Marvel universe.

The origin of the Brood has never been revealed. This is what is known about them:

Despite their resemblance to insects, the Brood have endoskeletons as well as exoskeletons. Also unlike insects, they have fanged jaws instead of mandibles. Their skulls are triangular and flat, with a birthmark (different for each Brood) between their large eyes. Their two front legs are actually long tentacles they can use to manipulate objects. There are two basic types of Brood: the smaller, winged ones, (who were nicknamed "sleazoids" by Wolverine) and the larger Brood Queens. The sleazoids have flexible abdomens that they need to coil most of the time, and have transparent wings. The Queens are wingless and have round abdomens.

Due to their natural body armor and teeth, the Brood are very dangerous in combat. In addition, they have stingers that can deliver either paralyzing or killing poison, as they will. Sleazoids can fly, while the Queens have the ability to implant Brood embryos in other beings. Unlike other parasitic creatures, these embryos do not grow their own bodies, but rather take over the host's, changing it into their appropiate form. It takes some time for the embryo to gain the ability to do this; in the meantime, the embryo can gain gain control of the host ocassionally, often without the host noticing (since they remember nothing while they're under the embryo's control.) If the host possesses any genetic powers, the resultant Brood will inherit them. What happens to the persona of the host once the Brood is "born" is not clear; it appears that it is extinguished, but in some cases, it survives and coexists with the Brood's. Some Brood have been shown as being able to switch back-and-forth between their host's form and their true one, even changing form only partially if they wish. (It must be noted that the Brood have not been written consistently by different writers, which may explain this, and other, features.) The Queens can also communicate with their spawn by telepathy, even across interstellar distances.

The Brood are fully intelligent even before they are "born". Apparently they pass on a racial memory to their descendants, possibly including some from their hosts.

The Brood aren't just savage, they're evil, intentionally enjoying the suffering they cause others, especially the terror their infectation causes their hosts. They've been compared to "demons". Given the incident with the Acanti Soulforce (see below) it may be that they have a supernatural origin.

The Brood have a civilization based on the typical communal insect societies, such as those of the bees and ants. The Queens are the absolute rulers, while the sleazoids do all the work; despite their evil, they never rebel against their Queens, perhaps due to the latters' telepathic abilities. It must be noted, however, that the Queens have no alliegance to each other. They also have developed advanced technology.

Their true planet of origin is unknown. They arrived in the Shi'ar galaxy long ago, and began infesting many worlds, becoming deadly enemies to the Sh'iar. In this galaxy they found certain large space-dwelling creatures that they decided to use as living starships. These include the whale-like Acanti, and the shark-like Starsharks. The Brood use a virus that effectively lobotomizes the creatures, then they use bionics to control them. The Brood hollow out part of the creatures (by eating them) and use the space created to live in, like termites eating a tree. This of course eventually kills the living ships, requiring them to capture new ones.

One of the Acanti they captured was of unusual size (its rib cage alone was the size of a mountain range.) They used it as their main base, and, when it died and crashed onto a planet, used it as their main city. (The corpse was so large, it took centuries just to rot halfway.) However, predators from the planet they landed on infested the area of the dead Acanti's brain, so the Brood avoided it.

The Brood allied themselves with the renegade Sh'iar Deathbird to help her depose her sister Lilandra as ruler of their empire; as a reward, Deathbird gave Lilandra, their allies the X-Men, and their human friend Carol Danvers (who had been the superhero Miss Marvel before Rogue stole her powers) and even one of her own allies, Fang of the Imperial Guard, to use as hosts. The Brood did indeed made use them, except for Danvers, apparently since they wanted to perform experiments on her half-human/half-Kree genes. The Brood created an illusion in which the heroes and their friends believed they were guests of the Shi'ar and didn't realize they were being implanted. However, Wolverine's healing power purged him of his embryo, and he helped his friends to escape (except Fang, who changed into a Brood before they left.)

The Brood Queen ordered her forces to find them, until she was contacted by the Queen embryo she had implanted on Cyclops of the X-Men; it explained that the X-Men were returning to "sleazeworld". Resigned to their dooms, the heroes were trying to accomplish one last good act by helping the Acanti race to recover the "Soulforce", an apparently supernatural force that must be passed from one Acanti leader (The "Soulsinger") to the next. The Soulforce was located in a crystalline part of the dead Acanti's brain. The Queen herself went with her minions to that area, and battled the X-Men until they started to change into Broods. The Soulforce was almost infected by the evil of the Brood. Wolverine tried to mercy-kill his friends (and then the Queen) but they were saved when Danvers (now a star-powered being called Binary, a result of the Brood experiments on her) arrived and released the Soulforce. Before it went onto its next host, the soulforce cured the X-Men and Lilandra, and turned the Queen into a crystal statue. It also caused sleazeworld to explode, but the X-men and their allies escaped alive.

Another branch of the Brood managed to reach Earth, and infected several people, mainly mutants, including many from the Louisiana Thieves' Guild that Gambit belongs to. The X-Men were forced to kill most of the infected people.

An exception was a woman named Hannah Connover , wife of reverend William Connover of the Glory Day ministry. She was implanted with a Brood embryo by paramedic Josey Thomas, partner of Queen-host Harry Palmer. Becoming a Brood Queen cured her hands of arthritis and she used this "miracle" to become a faith healer for her husband's ministry. She secretly infected the people who came to her for healing, curing them of their illnesses by converting them into her Broodlings. She eventually managed to overcome the Brood's control, a feat she attributed to her husband's unknowing inspiration, and rebelled against the Brood Empress. The Empress sent several of her unusually powerful "firstborn" Broodlings to assassinate her lest she interfere with the invasion of Earth. The X-Men were unable to stop them in direct combat but they were ultimately defeated when she allowed Iceman to freeze her solid, stopping her brain activity and cutting her off from Brood telepathy. Having lost contact with her the assassins believed her to be dead and their mission over, so lacking a ship to return home they killed themselves. She was later revived and she and her Broodlings left Earth. According to a the time-travelling X-Man Bishop there are benign factions of Brood in the future, and he speculates that Hannah may be their originator.

There are still malevolent Brood left in the Marvel Universe, however, and it is likely they will appear again in the comics.