Bayou

Situated between the Elemental Realms of Earth and Water, there is a small plane known as the Para-elemental Realm of Ooze, where water and earth intermingle into something amorphous, neither solid or liquid. But situated just above it, sandwiched between the Material Realm and the Negative Energy Realm, there is the Bayou. It is from this place that all other bayous, across all other planes, derive their name.   The Bayou is a massive swamp, left in perpetual twilight by the clustering branches which hang overhead. The branches of the trees stretch infinitely above, no matter how far one rises. Situated closely to the Elemental Realms of Earth and Water, all spells cast which deal with the elements of water and earth are treated as being cast using a spell slot of one level higher. The brackish waters and darkened soil which fill the Bayou are both highly responsive to the calls of spellcasters and other who would draw power from them, just as amorphous as the nearby Realm of Ooze. While closely situated to the Negative Energy Realm, the Bayou does not actually touch the realm. But the essence of the Bayou itself causes poison damage to be doubled, and causes all creatures in its confines to have disadvantage on saving throws made to resist poison and diseases.   Moving through the Bayou is a difficult and dangerous process, as the entirety of the Bayou is filled with water that rises ankle-deep in most locations, and in others the water levels reach up to the waists of even the largest of humanoids, and well over the heads of their smaller companions. All areas within the Bayou are treated as difficult terrain, unless they are locales of constructed terrain. The trees which cast a shadow over the Bayou filter out all but a small remnant of light, so that the Bayou is also in a state of perpetual dim lighting, reducing visibility of creatures unable to see in the darkness to 30 feet, or 60 feet with disadvantage on Wisdom (Perception) checks.   Life in the Bayou is very abundant, found everywhere one turns their head, and every last bit of it is incredibly dangerous, even to the most prepared of visitors. The Bayou is home to a number of extraplanar creatures found nowhere else in all the planes, as well as thousands found in all other locales. Beyond the Giant Alligators, enormous bloodthirsty insects, and other dangerous predators, there are hundreds of different types of plant creatures, both sentient and non-sentient. The dining habits of many of these plants fall on the carnivorous side, making them dangerous for visitors to approach. Plants that don’t actively try to eat visitors are still highly dangerous due to toxins and poisons, each with their own unique method of using thorns, barbs, and spores to leave travelers feeling ill. Attention to safety must be a constant in all areas of the Bayou. The Bayou also influences strange changes on creatures which might otherwise prove no threat, turning them into savage monsters capable of gutting unwary adventurers with a toss of their head, while oozes living within the Bayou benefit from the plentiful food and resources they naturally thrive on. Any creature of the beast or monstrosity type automatically gains the Dire template, and all creatures of the plant type have their size increased by one level, giving them advantage on all Strength saving throws and ability checks. Creatures of the ooze type have twice the maximum number of hit points.   Though the Bayou is incredibly dangerous, there are still a few small populations of intelligent creatures which reside in the Bayou. These places are incredibly sought-after safe havens if they are friendly to outsiders, selling supplies gathered from the debris of the swamp, and often offering places to rest and recuperate. Others are not so friendly, and outsiders caught in the territory of these populations face other dangers associated with those individuals. Various slaad, hags, yuan-ti, and supposedly even ooze-worshiping warlocks stalk the trees and fetid pools of the Bayou, preying on the more common bullywugs and grung which also live there. Beyond these dangers, elementals from the Realm of Earth and Water find great difficulty in entering the Bayou, as it is much closer to the level of the Material Realm, and cut off from all but the most primal of their elemental energies. Therefore, despite its relative closeness in the planar cosmology, elementals are very few and far between in the Bayou unless otherwise summoned by outside casters, though these casters might find calling upon such creatures to be much easier than normal.   All in all, a trip into the Bayou should never be made unprepared. And for those who do prepare, extra precautions should always be made. A week’s worth of supplies might suddenly vanish into a quicksand bog, or be engulfed in the mouth of a monstrous crocodile, leaving travelers with no other option but to seek out intelligent company, and all of the dangers that may other entail.