The swamp is a natural hazard. When unseen forces are allowed to fester and grow within this fecund biome, it is the unnatural that becomes the true threat.

Unearthed Spoils #037 - Mirebound Menaces contains the following content:

• DECAY DOMAIN - These clerics embrace the cycle of death, rot, and rebirth with necrotic power of a divine nature.
• CIRCLE OF THE MIRE - Harnessing the swamp’s power, these druids conceal their secrets, control terrain, and unleash decay.
• BACKGROUND: BOG DWELLER - Raised in the bayou, you are a survivor by nature and a stealthy navigator of the swamp.
• SWAMPLAND SPELLS - Spells of mist, mire, fungus, and decay for arcane and divine casters.
• FENTASTIC ITEMS - Wield these magical creations from the mire, and you’ll be swamped with power.
• BOG BEASTS - Discover a generous swath of mirebound threats for marsh travelers and swampland adventurers alike.
• 3rd-LEVEL ADVENTURE - A swamp is a dangerous place at the best of times, but the strange events in Vexwood Marsh have the folks in nearby Duskwater desperately seeking relief.