An oil spill mutated a small single-celled organism, creating a monster that had a living breeder reactor inside it, who began absorbing any material it could find. The crew of the Calico encountered the monster and called Godzilla. Godzilla's fire breath ignited pockets of unassimilated matter in the creature, causing several small explosions inside it and forcing it to withdraw. Later, it attacked a natural gas plant, and afterwards, it attacked Washington D.C. The military and Calico crew tried to stop the creature without explosives, thinking that explosions inside the Breeder Beast at this stage could cause a nuclear explosion. The monster went to the U.S. Mint and absorbed the gold, silver, and precious metals in it. Before long, Godzilla attacked it with his laser eyes, and instead of a nuclear reaction, the beams only harmed the monster. Realizing that the Breeder Beast had control of its internal reactions, the crew instructed Godzilla through Godzooky to fire his lasers at the nucleus of the monster. The materials that the Breeder Beast had consumed crystallized and escaped from the creature's mass, which began to shrink, leaving behind the original microorganism.
- The Breeder Beast has a protoplasmic mass that can stick to and pull objects into its body.
- The Breeder Beast can extend numerous pseudopods to grab things.
- The Breeder Beast is really good at throwing objects.
- The Breeder Beast is an adept swimmer
- Any material that can be ingested or absorbed into its nucleus is used to increase the Breeder Beast's size, mass, and presumably powers as well.
- Fire and explosions could set off an explosive reaction until the creature became in control of its reactions, enough damage to the nucleus will cause the raw material in the Breeder Beast to crystallize out of the creature.
- The Breeder Beast bears some resemblance to the larval Mothra.
- It is similar to the giant amoeba from the 2001 film Evolution.