Brood

One of the Brood's earliest known conflicts was against the Eidolon Host; warriors clad in intelligent "warwear" body sheaths. Subsequently, the Brood made enemies of both the Shi'ar and the Kree. Capturing Kree Admiral Devros, the Brood infected him with a royal embryo. Devros then came to perceive himself as the Brood King, a perfect synthesis of blue-skinned Kree military facility and Brood physical prowess, and sought to similarly convert the other blue-skinned Kree while transforming the pink-skinned Kree into drones. Devros and the Brood were opposed by pink-skinned Kree Captain Mar-Vell. Though he slew both the Brood Queen and Devros, Mar-Vell himself had been infected and began transforming into a Brood King before he was saved by Medic Una, who used a modified Omni-Wave-Projector to destroy the embryo within him.

The Brood have since repeatedly clashed with Earth's X-Men. The Brood had allied with the rebel Shi'ar warrior Deathbird, who was seeking to gain control of the Shi'ar Empire from her sister, Lilandra Neramani. Following Corsair, leader of the space pirates the Starjammers, to Earth; the Brood were opposed by the X-Men. During the encounter, the Brood Warrior-Prime, Skur'Kll, was slain by Wolverine, beginning a long-standing mutual hatred between the feral X-Man and the Brood. The Brood later returned, led by the Imperiatrix herself, and captured the mutant heroes, implanting each with a Queen embryo. Wolverine's mutant healing factor was able to purge the embryo from his system; however, Storm began transforming into a Brood. Swept out of an airlock before the change could be completed, she was saved by an infant member of the Acanti who was destined to be a Prophet-Singer, its race's new leader. Bonded physically and psychically to the baby Acanti, Storm and the X-Men agreed to help liberate the Acanti from the Brood's enslavement and located the Acanti's racial soul in the corpse of the Acanti's former Prophet-Singer on the Brood's homeworld. After a pitched battle, the energy of the soul purged the embryos from within the X-Men and crystallized the Imperiatrix as it destabilized the planet, causing it to explode.

Returning to Earth, the X-Men discovered that the Brood had implanted their founder Professor Charles Xavier, with a Queen egg. Under its control, he had formed a team of trainees called the New Mutants, which the Queen intended to be Brood hosts. The Queen transformed Xavier's body, but the X-Men and New Mutants were able to delay it long enough for Xavier's mind to reassert control. Xavier ultimately survived after his mind was transferred into a cloned body created by Sikorsky of the Starjammers. Later, one of the surviving Brood Queens encountered the New Mutants' Magik and her ally Lockheed, an alien dragon whose race, the Flock, are long-standing enemies of the Brood.

Seeking revenge on the X-Men, the Brood again attempted to invade Earth. Implanting paramedic Harry Palmer with a Queen egg, the Brood sent him out to infect mutants, hoping to create a Brood force with abilities to rival those of the X-Men. Attempting to ambush the mutant heroes, the Brood-infected mutants - Blindslide, Brickbat, Dive-Bomber, Lockup, Spitball, Temptress, Tension, and Whiphand - gained the upper hand initially; but after realizing that the hosts were beyond saving, the X-Men slew the Brood mutants in pitched battle. During the fight, Palmer's medic partner Josey Thomas, also Brood, implanted Hannah Conover, wife of Reverand William Conover, with a Queen egg, hoping to establish a beachhead on Earth. Under the guise of faith healing, Conover began to create a force of Broodlings loyal to her.