Xibalba Seeders are a race of humanoid plants in the horror or science fiction genres.
Their origins are most probably alien, but the race has existed on Earth for many millenia.
Their existence is not public knowledge to the people of the planet, though certain organizations and government agencies are aware of them.
Xibalba Seeders look completely human, and are all male. The only difference to the naked eye is their blood, which is a clear amber color, like sap.
They draw energy from the sun, like ordinary plants, but instead of drawing nutrients from soil, they ingest them as humans do, through eating. They breathe carbon dioxide, and exhale oxygen.
Xibalba Seeders breed by sexual reproduction with humans. It is thought that it is this combination and copying of human genes that allows them the human form, and that the original Xibalba form is probably a lot more plantlike and alien. The ability to assimilate genes from other species must be an advanced adaptive trait crucial to their survival.
In the act of reproduction, the Seeder appropriately plants a seed within the womb of the human female.
Within an hour, the seed has assimilated the host's genes and begins sending roots into the body of the mother. The roots gather moisture and nutrients from the mother/host, and the seed begins growing at a rapid rate. Within 6 hours, the mother's pain is crippling, and within 8 hours, a stalk or trunk-like plant begins growing out from her navel. Within twelve hours, the host is nearly dead, and a 3-5 foot tree like plant is growing out of her stomach. A fruit begins ripening on the tree, this is the embryonic stage.
In another 6 hours, the host is completely dessicated, all moisture having plumped the tree's fruit to about 10 lbs. At that point, the fruit drops from the used up host, and the dried and used up tree, and the juvenile Xibalba is hatched out of the fruit, much resembling a human infant, but farther along in development. The infant is immediately able to walk on its own, has teeth, and immediately starts seeking out food and sunlight.
Xibalba Seeders grow extremely fast, with almost 80% of the matter they ingest becoming new body material until they reach an adult size. Depending on the food and light available to the infant Xibalba, this could take as long as 3 months or as short as 2 weeks. They learn almost as fast as they grow, and each possess eidetic memories.
The lifespan of a Seeder is nearly infinite, provided all the neccessities of their life, and no structural damage. There are few diseases that affect Seeders, as viruses and bacteria that would attack humans will not attack the plant-based cells of the Xibalba. Some plant diseases can affect them, but even this is a rarity. The Xibalba avoid breeding with humans with genetic defects that may be assimilated with a combination of screening by senses much more sensitive than those of humans, and an extending 'courtship'. This courting period may be an extended observation of a prospective mate, much like 'stalking', or it may take the form of an actual relationship. In such a way, the Seeder spends some time choosing its mate carefully, as it only becomes fertile once every seven years.
It is unknown just how long the Xibalba have existed on Earth, but it is said that their population took up residence in the jungles of Central America, and lived there alongside the human population for awhile before being cast out and forced 'underground' by the Mayans. For a few centuries, they remained secreted away in the deepest parts of the rainforests until the first vestiges of an expanding western culture and society encountered them again, allowing them entrance into a far larger world than they have ever previously known.