It came from Hadal Forest

They say that 90 percent of the world's oceans have been unexplored, due to just how much floor there is to cover. Imagine a world where, instead of deep trenches of water, our oceans were filled with forests—endless forests—where the further you go, the stranger, and larger the creatures become. The air growing thicker, and heavier, with the stinging sharpness of ozone; trees that stretch into the stratosphere, or bottomless muddy quagmires that are so deep that the bodies claimed can never be discovered; deer the size of whales, or bigger still, with an anomalous number of legs; the oppressive daytime darkness, never ending, due to the boundless appetite of the trees. Who knows what untold methods of ravenous mutilation might be discovered in the great beyond; or what unfathomable treasures lurk just beyond the shadow's edge. We find ourselves marooned in little islands of flat plain in the midst of miles and endless miles of oppressive wooded wilderness. Do not let the sunlight fool you. There is nothing keeping the terrors of the depths from venturing into the light.