When was the last time a character caught a cold or flu? Real people get them every now and again even with solid heating and dry interiors. Your characters are out in the cold and wet, and even inside is not always dry and warm. Imagine having to stop your dungeon crawl, sitting in a tight defensive position, while you all are feverish.
Arkths or Ravagers: These are large landbound crablike creatures about the size of Grizzly Bears. They live partially in the astreal plane. Their food is magic. They can sense it at huge distances. Since spells and such are hard to eat (being in motion) and magical places are the equivalent of a sea of krill to them, they are looking for magic stashed in concrete places. Their primary food source is magic items, alchemical potions, and enchantments. They do a pretty good job of mangling/ eating the physical aspect of said items in the process of chowing down. These things will be the bane of dungeons everywhere, as they will slowly eat away much of the treasure (and the magical traps... so it can be advantagous to follow these things). Note: They will attack people with highly magical natures (i.e. high magic powers). They will probably kill the person in the process of sucking out the power.
Khor are a monsterous and violent race. Within five years of being born, they grow to about half human size and are very, very inteligent. As they get older, they get larger... unfortunately they become less intelligent. After their adolecesence (about seven years), they grow to human size and are of a low human intelligence. As they age, they grow larger, slower, and stupider. Most of them end their lives 3 to 4 meters in height. Khor have been reported upto 10 meters tall, though those elder giant Khor do little but hit anything that disturbs them.
As they age they get larger, they don't seem to ever die of natural causes.
After particularly intense storm, a green glowing fungi can be found on the trees and plants. Also new monsters seem to be in the region. These storm are obviously bringing these things from other places and depositing them with the wind, rain, and goop upon the land.
Molk Peruda is encountered by the PCs on the second day of their journey west from the salt-choked port of Quyn, as they prepare to explore the jungle.
He appears a gaunt, wolfish man, with matted, dark hair that sprouts from his head in dreadlocks, contrasting with his well-oiled, blue-black, conical beard. His eyes are hidden ebon shards beneath thick arching brows, his nose, crooked, long, and reminiscent of a snout. His mouth is a thin, dark line, his teeth unseen even when he parts his lips to speak.
His skin is the color of tallow, surprising perhaps for a renowned jungle guide, yet his natural helm of dreads and the jungle's canopy keeps the sun from bronzing his originally pale flesh. On his back are tattooed three women from the waist up, side-by-side, each resembling the other but of different ages. This is a tattoo of Molk's mother, sister, and daughter. His wife (don't bring her up to him!) was killed by marauding Qullan years ago, and appears as her own tattoo on his broad but sunken chest.
His feet shockingly are turned around 180 degrees at the ankle, facing towards his back! A curse from a pernicious shaman. Molk walks feet backwards (he's used to it) and walks backwards, forwards. This can be very disconcerting and outright creepy to the PCs as he guides them through the rainforest.
Slung from his back is an archer's quarrel of treated wood carved to resemble a stalking leopard, in his hand a re-curved composite bow of horn and sinew, with a pair of vivid, red eyes, each one painted on the opposite side of the hand-grip. In a leather sheath at his belt, hangs a falchion, its pommel adorned with a curved bird's head and beak.