The Brood are insectoids beings travelling through space to found host to their spawn.
They aren't just savage, they're evil, intentionally enjoying the suffering they cause to others, especially the terror their infection causes to 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 latter' telepathic abilities. It must be noted, however, that the Queens have no allegiance 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 lobotomises 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, forcing the Brood to avoid it.
First encounter with the X-Men
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 make use of 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. Some of the Brood also managed to escape before the planet exploded. The new Soulsinger then led the Acanti to safety in deep space.
Some of those Brood landed in the United States southwest. They made their way to Dallas, where they infected a number of mutants. However, they were ultimately defeated by the X-Men.
Another branch of the Brood managed to reach Earth and infected several people, mainly mutants, including many from the Louisiana Thieves' Guild that Gambit belonged 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 the time-traveling X-Man Bishop there are benign factions of Brood in the future, and he speculated that Hannah may be their originator. However, there are still malevolent Brood in the Marvel Universe.
Later still it is revealed that seven of the Brood's most elite warriors, the Warriors-Prime, were swallowed by a predator deep within Sleazeworld just before the destruction of the planet, and the explosion crystallized the creature, preserving the Brood. They drifted through space until they were drawn into the portal to the planet Sakarr. There they were freed from their crystal prison and entered into a battle with various other prisoners of the the Red King, where six were slain. The seventh, known as No-Name, survived and was placed on a gladiator team with the six other survivors, one of whom was the Hulk, who had been sent there by the Illuminati. She fought with the Hulk when he overthrew the Red King and became the new ruler, and followed him to Earth to enact revenge on the Illuminati, who they believed had destroyed the planet. After the events of World War Hulk, she remained on Earth and stayed with the Warbound to watch over the Hulk.
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. Sleazoids can fly, while the Queens have the ability to implant Brood embryos in other beings. The Queens can also communicate with their spawn by telepathy, even across interstellar distances.
The Brood are parasitic and must steal the bodies of others to reproduce, making them one of the most insidious alien menaces in the Marvel universe. Unlike other parasitic creatures, these embryos do not grow their own bodies, but rather take over the host's, changing it into their appropriate form. The embryos are also fully intelligent even before they are "born". Apparently they pass on a racial memory to their descendants, possibly including some from their hosts. It takes some time for the embryo to gain the ability to take over its host; in the meantime, the embryo can gain control of the host occasionally, 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. 
The Brood have shown to be able to infect and transform many species, such as the humans (including mutant, Shi'ar, Kree. The mutant/alien hybrid and S.W.O.R.D. agent Brand was longer to be fully infected, Brand stating her half-alien physiology was in cause of this resistance.
The Brood DNA has been shown to be crossable with many beings, first by their infection system, but also by bio-engineering, crossed with numerous beings, such as Krakoa, or human mutates, as Man-Thing and Sauron (Described specimens of Krakoa and Sauron giant Brood clones).
Benign Brood & Mutants
On Earth-616, we have seen two specimen of such Brood: No-Name, and the mutant brood Broo (who has lost his compassion since). Both were intended to be used as a template for the hive-mind of this incoming race.
This kind of Brood are supposed to be killed at their birth by the "normal" Brood, as an eugenic system.
In this reality, Christopher Summers would be infected with a Brood Queen embryo before escaping to Earth. There he would be captured by the forces of Apocalypse and experimented on by Sinister and the Dark Beast. After six years of torture, he would escape unaware of his infection. His Brood half would begin to assert it's control and infect all the humans it encountered including Joe Robertson and Colleen Wing. Summers would be hunted down by the Elite Mutant Force which included his two adult children Scott and Alex. The EMF would slay all those infected by the Brood, and Scott himself would be forced to kill his own father.
It is interesting to note that in this reality those infected with the Brood (with the exception of Chris Summers) had to physically die before the embryo could hatch. The reason behind this remains unexplained.
Powers and Abilities
The Brood are really resistant, due to the fact they possess endoskeletons as well as exoskeletons.
Their tentacles are long enough to be use to manipulate objects on large range.
In combat, they used both teeth and stingers that can deliver either paralysing or killing poison.
The Sleazoids possess wings allowing them to fly, while the Queens have the ability to implant Brood embryos in other beings. The Queens can also communicate with their spawn by telepathy, even across interstellar distances.
Average Strength level
Type of Government: Hive Monarchy/Genetic Caste System (as in Bees and Ants)
Level of Technology: Highly advanced
Cultural Traits: Warrior culture, utterly savage, driven solely by hunger and procreation
Representatives: "Mother-of-us-all" (Queen)
- The Brood returned to Earth in the second Ms. Marvel series to battle Carol Danvers, who as Binary played a key role in their first defeat.
- Some Brood Sleazoids appear in the arena of planet Saakar in the Planet Hulk storyline of The Incredible Hulk, one of them even becoming a main character.
- Brood also appeared in X-Men Legends II: Rise of Apocalypse
- Discuss Brood (Race) on the forums
- Appearances of Brood (Race)
- Race Gallery: Brood (Race)
- Images of Brood (Race)
Links and References
- Uncanny X-Men 155-156, first appearance
- Uncanny X-Men 161-167, X-Men infected, destruction of "sleaze world", death of the "Mother-of-us-all", the classic brood storyline. (A continuation of 155-156 over-arching storyline).
- Uncanny X-Men 232-234, second brood storyline, first time X-Men battle a group of super-powered brood.
- X-Men 8-9, Ghost Rider Vol 3 26-27, X-Men/Ghostrider Crossover, brood in New Orleans and in sewer tunnels
- Quotes by the Brood