The Sylvalagi are a secret competitor species to humans. Many unexplainable phenomena, such as UFOs, the Bermuda Triangle, cryptic strangers, mysterious disappearances, and much more, can be attributed to their clandestine activities.
The Sylvalagi can be distinguished from humans by their additional appendages and animal characteristics. Some Sylvalagi have horse- or rabbit-like ears and tails, others additional sets of upper arms. Several Sylvalagi subgroups descend from genetic experiments and military bioweapons productions, and may resemble centaurs, demons, cthulhu, or even worse creatures.
Sylvalagi consider themselves vastly superior to homo sapiens humanity, and they mean to eventually eradicate the inferior species. However, the Sylvalagi society has suffered a major collapse during the last two centuries. Since that time, constant inter-clan warfare has decimated their ranks, and unleashed a veritable hell-horde of biological, chemical, and genetic weapons. Humans are spared their full attention, while the major Sylvalagi groups fight each other for world domination.