Most of the plants and animals found in the Well will be completely new to the average PC visitor. Some of this is due to the multi-dimensional nature of the Well, some due to the genetic tinkering of the Snake Men.
The bulk of the Well’s animal life comes right out of the book The World Of Kong: A Natural History Of Skull Island. While the book itself is out of print, I have a fairly complete break down of the creatures (in HERO System 5E terms).
Of the creatures listed, I recommend removing Kong, as this is the Well of the Worlds, not Skull Island. However, the rest of the creatures are sufficiently generic enough that you could use them and not arouse suspicion in your players. Other creatures that could inhabit the Well include mammoths and mastodons in the Foothills and Uplands, immense fish and/or sea serpent like creatures in the Ring Ocean, “dragons” (probably some sort of dinosaur-like creature), and just about anything else you can think of that doesn’t require a “magical” background explanation to exist
The plant life of the Well is incredibly diverse. Much of it should seem fairly exotic to the PCs, although, in truth, real world plant life can be pretty strange as is. Personally, I highly recommend The Private Life of Plants (with David Attenborough) for an idea of what to expect in the Well. Some suggestions:
Bristlecone Pines (or the equivalent) along the edges of the Foothills. Player Characters will find forests of seemingly dead trees with only small scattered clusters of needles along the tops. These trees are all easily thousands of years old.
Cushion Plants grow in dense mats across the Uplands. These are thick masses of tiny plants that only grow to be few inches high, put are packed so tightly it’s nearly impossible to separate them.
The Jungle Ring is a riot of strange plant life. Aside from immense trees, Strangler Figs, creepers and vines, there should be carnivorous plants big enough to eat birds, land animals, and (naturally enough) people. Examples include giant-sized Venus Flytraps, Pitcher Plants, and Sundews. On a more benign side Giant Elephant Ears plants produce leaves of immense size (up to eight feet long and 30-40 square feet in total area), and the parasitic Rafflesia can produce flowers three to four feet across.
Lakes can be covered by immense Water Lilies several feet across, while the shallow Ring Ocean is perfect for Giant Kelps, which can get upwards of 200 feet in length.
Game Masters can easily create additional plants to both help and hinder the PCs.
The Well has an extensive native population, composed mostly of Farming People, variant Farming People, and human(oids) with secondary animal characteristics. A more detailed breakdown is a follows:
Farming People Random Skin Color
Die Roll Color 2 Pure White 3 Gray 4 Purple/Violet 5 Blue 6 Blue 7 Green 8 Yellow 9 Orange 10 Red 11 Gray 12 Dead Black
FARMING PEOPLE: Farming People are the most common inhabitant of the Well, and are known as "The Building People" in some places. They are used as the basis for the bulk of the Snake Men’s genetic experiments. The average Farming Person inhabitant of the Well appears as a rather tall human, standing 5’8” to 6’ for men, and 5’6” to 5’9” for women, and in excellent physical shape, both strong and hardy. They’re also rather colorful, with skin (and hair) colors ranging from dead black to pure white, and just about everything in between. The most common colors are blue, green, and red, with some yellow and purple. Hair color usually matches skin tones, but not always. There are more “normal” appearing Farming People as well, who have light tan to light brown skin, dark eyes, and dark hair.
BURROWING PEOPLE: Short (4’-5’ tall) humanoids with broad, muscular builds. They have grayish skins with red, brown, black, or gray hair. They tend to dwell far up the Well, in the Uplands and Foothills, where they dig mines and burrow out huge underground homes. They are excellent metalworkers, and tend to trade their work for foodstuffs they can’t grow or find on their own. They are also known as “The Digging People,” or "The Mining People."
FOREST PEOPLE: Forest People are Forest and Jungle-dwelling feral Farming People. They tend to greenish skin and hair, with long fingers, prehensile toes, and long tapering ears (the PCs may think they look a bit like elves). Excellent climbers, they live mostly in the trees, where they roam about in large family groups, living off of the land, as hunter-gatherers.
GIANT PEOPLE: Humanoids that stand upwards of 10 feet in height. They are covered in hair and look like a cross between a chimpanzee and a gorilla. At best guess, a Giant Person is a form of early simian, perhaps a Gigantoithecus. Giant People raid settlements for crops, livestock, and people, and will eagerly eat anything they catch.
HUNTING PEOPLE: Shorter then Farming People, Hunting People average about 5’4”-5’6” for females and 5’7”-5’9” for males, with lithe and supple builds. They have classic anime “cat-girl” looks—vertical pupils, cat’s ears, sharp teeth, tails, and so on. They tend to have pale to white hair and tanned/bronzed-skinned bodies (they aren’t furred). Hunting People are always fit in appearance and exotically attractive.
LEAPING PEOPLE: Averaging 5’6” to 5’8”, Leaping People are a race of humanoid rats/ferrets/kangaroo rats. Noted for their agility (although not as agile as the Hunting People), Leaping People are, as their name implies, great leapers, able to clear distances of 9 to 10 feet (or more) from a standing start. Their bodies are furred and very slender. They also have human-like hair on their heads, thin, smooth-furred tails, and legs that digitigrade.
NIGHT PEOPLE: The Night People appear as “feral” Forest People (if that’s even possible). They’re shorter (5’-5’6”) then the typical Farming Person, with blueish to grayish skins. They live in the Uplands and the Jungles and tare said to steal livestock, steal harvests, kill the unwary, and eat the dead. They are also known as “The Scavenging People”, “Night Thieves”, “The Quiet People”, and due to various rumors “The Eaters of the Dead (and/or Slain.)”
RUNNING PEOPLE: On average very tall (an adult Running Person stands at least 6’ in height), with long legs, tanned or brown skin, and pale or white hair, the Running People appear as lanky Farming People with long ears atop their heads. Very fast runners, they prefer the lower parts of the Well, but will come up from the Plains to trade. Common wisdom is to never challenge one (or accept a challenge) to a footrace.
Chimera are the humanoid/animal cross-breeds created by the Snake Men.
BEAST PEOPLE: These Forest and Jungle dwellers have the heads, arms, and torsos of Farming People, Forest People, and Hunting People with the legs of either deer, horses, or goats. Like the Forest People (who they often associate with), they’re hunter-gatherers who live in large tribes. Beast People normally go armed, with spears and bows, and have tangled with the Night People in the past.
SERPENT PEOPLE: An attempt to cross humanoids with reptiles. Serpent People have a Farming People, Forest People, or Hunting People heads, arms, and torso, with 15’-20’ of snake-like lower body. They dwell in the Forests, Jungles, and Plains, usually near lakes and rivers. Rare, they tend to be aloof and have minimal contact with the other races. Many people attribute magical powers to the Serpent People.
Note: although the Serpent People are creations of the Snake Men, they aren’t servants to them. Although they have snake-tails, Serpent People are warm-blooded.
WATER PEOPLE: The Water People are mer-people. They come in two varieties—fresh and salt water. Freshwater Water People have the heads, arms, and torsos of Farming People and Forest People, with finely-scaled fishtails. These tails are brightly colored with a broad fin at the base. Skin and hair tend to be fair in color, although the hair might be greenish or bluish. Saltwater Water People replace the fishtail with a dolphin-like lower body. They have darker skin (often bluish or grayish) and hair and smooth, scaleless tails with flukes. Both types of Water People breath air and live in shallow waters. They swim by moving their tails in a vertical motion (just like all cetaceans), with the saltwater Water People far faster than the freshwater ones. Like the Serpent People, Water People are warm-blooded.
The Reptile People are the true masters of the Well (at least for now). In truth, the Lizard People are the servants, shock-troops, and slaves to the Snake Men, who are the masters of the Well and many of its secrets.
Lizard People: The Lizard People are pretty much the Drakkine as described in The Turakian Age. Easily 7’ in height, they appear has humanoid lizards, resembling bearded dragons, with heavy scales, short spikes along the body, and long tails. They’re intelligent, have a language, and can use many of the tools and weapons of the Snake Men. Omnivores, they eat fruits, vegetables, and meat. Rumor has them eating humanoids.
The Lizard People are also called “The Scaled People.”
Snake Men: The Snake Men look like 20’ monitor lizards with no rear legs. They are highly intelligent, technologically advanced, and look upon the humanoids as test subjects for their genetic experiments. They aren’t ‘evil’ so much as amoral, or, more accurately, have a set of morals that doesn’t include the mammals. As a race they are older than Farming People, and have a certain degree of arrogance. Their history states they came to this world from their own (they don’t say how), and made it theirs—thus, all of the ‘late comers’ (i.e. everyone else) are trespassers on ‘their’ domain.
As most people never see the Snake Men, they don’t have a common name. They tend to refer to themselves as “The Chosen-” or “Superior-” People.
Game Masters have two choices with regards to the idea of halflings (i.e. cross-breeds). They are: realistic and pulp. With realistic, the various humanoid races and chimera are sexually compatible, but rarely (if ever) produce offspring (as seen in the Ringworld series.) With pulp, all of the various races can interbreed (much like what you get with Star Trek, Terran Empire, and John Carter of Mars.)