The foliedi is a six limbed, hermaphroditic, mammal. It has two conjoined bodies, the front and rear bodies. It has two arms and four legs. All the legs have knees. The front legs are digitigrade with short stubby toes and a stubby opposed thumb. The shorter rear legs are plantigrade without heels and with long dexterous toes and an opposed thumb, like hands. The primary source of power for movement is the front legs, while the thin back legs serve to support the rear end. It stands with its front body vertical over its front legs and its rear body sloped down so the rear legs can reach the ground. There is a small hunch over its rear shoulders where the ligaments that hold the forward body upright anchor. It normally walks on all four legs with its front body vertical over the front legs, but it can bend over, pull up its back legs, and walk on just its front legs. It always bends over and moves on its front legs when it has to move faster than a walk.
 It has no fur, just short thin hair spread over its body, with the exception of the head which has thick long hair covering all but its face. It needs to wear clothes all over to keep warm in cold conditions.
 Its mammary glands are on its front body only. Its penis and testes are located between its rear legs with its vagina opening located just in front of the base of the penis. Two will normally mate facing each other, with both penises entering the others vagina simultaneously.
 Skeletal system
 The front body is human normal down to the second lumbar vertebra. The third and fourth lumbar vertebra are ball and socket jointed. The fourth lumbar vertebra of the front body is ball and socket jointed to the first thoracic vertebra of the rear body. The rear body is more like that of a quadruped. The rear shoulder blades extend down along the sides of the ribcage. The front hips extend back and fuse with the front of the rear shoulder blades. The front legs are the hind limbs of the front body. The rear shoulder blades connect to the ribcage with strong ligaments for support. The rear lumbar vertebrae are flexible. They have ligaments that keep them straight normally. The rear sacrum is five fused vertebrae and it is followed by a coccyx. The rear hips are short and small.
 Cardiovascular system
 The two bodies cardiovascular systems are kept separate from each other. There are two separate four chamber hearts to pump blood through each system and two separate spleens. In place of lungs, the rear body has fixed size exchange organs which contain blood from both bodies. The capillaries from the front body form a U shape while the capillaries from the rear body overlap those of the front body in an N shape. There are two overlapping regions. The one where the blood is flowing in opposite directions cause a maximal exchange of oxygen from the front body for carbon dioxide from the rear body. It causes a maximal transfer of waste material from the front body intended for the kidneys in the rear body. It also causes a maximal transfer of hormones from one body intended for the other body. The overlapping region where the blood is flowing in the same direction equalizes the blood pressure in both bodies by transferring water. It equalizes the nutrient content of the blood from both bodies. It also equalizes hormones intended for both bodies. Some hormones are not transfered at all, most notably the reproductive hormones. The exchange organs also perform the function of kidneys for the front body in terms of releasing hormones that regulate blood cell counts.
 Respiratory system
 The front body contains the fixed size lungs, like bird lungs. The air passages connected to the air sacs and lungs are valved to let air go through the lungs in only one direction. On inhale, some of the incoming air goes down through air passages that connect to the posterior air sacs located around the exchange organs in the rear body. The rest of the air goes through the lungs into the anterior air sacs located around the lungs in the front body. On exhale, air comes from the posterior air sacs, goes through the lungs, combines with air from the anterior air sacs and is expelled from the body.
 Digestive system
 The digestive system is designed to process tough fibrous plant material. The front body has a four chambered stomach. The first chamber hosts bacteria that can break down the plant fibers. Once the plant material is introduced to the bacteria, it is partially regurgitated into the gizzard which grinds up the material and mixes in the bacteria with the aid of small sharp rocks. Then the plant and bacteria mixture passes through the stomach into the duodenum. Bile and digestive enzymes are added from the liver and pancreas. The liver, gall bladder, and pancreas are inside the front body but they are fed blood from the rear body cardiovascular system. The duodenum is part of the rear body. The duodenum passes through the rear thoracic cavity, past the rear diaphragm, to the small intestine, which takes up most of the space in the rear abdominal cavity. The small intestine absorbs nutrients from the digested plants and bacteria, and passes the rest to the large intestine. The large intestine absorbs some more nutrients and water from the mixture. The waste material is passed to the rectum to be ejected out the anus.
 Urinary system
 The kidneys and bladder are located in the rear abdominal cavity. The bladder empties out through the penis.
 Neurological system
 The two bodies have separate neurological systems. There is a membrane in the first rear thoracic vertebra which separates the spinal fluid from front to rear. The membrane is heavily wrinkled and covered in synapses to transmit information between the two systems.
 It is instinctive behavior for the rear legs to walk forward when the rear body is pulled forward. This motion is coordinated with the motor control signals to the front legs to avoid tipping to one side. It is instinctive behavior to raise the rear legs when the rear body is lifted up. These instinctive behaviors come from the gray matter in the rear spinal column. There are additional synaptic connections to the motor control center of the brain to allow learning independent control of the rear legs.
 Touch sensation is spread out over the two torsos. It takes twice the distance as in a human to separate two distinct points of contact. Touch sensation in the arms and legs are just as sensitive as in a human. The sensations from the rear legs go to a new sensory area of the brain. Touch sensation on the tip of the penis is overlaid with touch sensation on the clitoris.
 The signal to the rear diaphragm comes from the same source as the front diaphragm, they move together.
 Reproductive system
 The penis and testes are part of the rear body. The vagina, uterus, and ovaries are stretched out over the length of the rear abdominal cavity, but are fed blood from the front body. This keeps the reproductive hormones separate from each other. The foliedi has a human normal menstrual cycle.
 The DNA is the same in the front body and the rear body. It has two X chromosomes. The rear body has epigenetic markers on it's active X chromosome that cause it to act like a Y chromosome. These markers and other markers that differentiate the front body from the rear are maintained through mitosis but are removed as part of the meiosis process in both the testes and ovaries.
 Development
 The first difference from normal mammalian development occurs in the blastocyst phase. The inner cell mass is divided into two conjoined nodes. One of the nodes has the epigenetic markers for the front body while the other has the markers for the rear body. As the masses stretch into disks, the junction between them becomes a straight divide. The cellular movement of the epiblast of the front body is around the outside and towards the junction, forming a primitive streak against and perpendicular to the junction. The cellular movement in the rear body is around the outside and away from the junction, forming a primitive streak away from and perpendicular to the junction. Each body develops its own yolk-sac. Cells at the junction form a membrane between the front and rear bodies. The membrane is two cells thick, one side of the membrane is the front body cells, the other side is the rear body cells.
 Primitive arteries and veins from the front body extend into the rear body surrounded by the junction membrane. Arteries fed from the right ventricle and veins from the left atrium extend into the gaps in the junction membrane. The junction membrane forms the primitive exchange organs. The umbilical cord connects only to the front body, the rear body gets nutrients and oxygen through the primitive exchange organs. The rear heart has four chambers early in the development cycle.
 Cells from the rear body enter into the front body along with the primitive digestive tract, surrounded by the junction membrane. The cells will form the liver, gall bladder, and pancreas. The digestive tract will form the duodenum. The rear primitive digestive tract connects to the end of the front primitive digestive tract. The junction membrane cells open up at the connection point of the digestive tracts.
 Cells from the front body, surrounded by the junction membrane, make their way down to the rear abdominal area. These will form the ovaries, uterus, and vagina. The junction membrane will open at the opening of the vagina, causing the skin cells to form an opening in that area.
 The front hips develop parallel to the spine. The junction membrane opens up between the front hips and the rear shoulder blades, allowing them to fuse. The junction membrane extends around the outside of the rear shoulder blades forming connection points for the tendons from the front legs.
 The embryo develops into a fetus. The fetus is curled up on itself, head to rear. Pregnancy takes the same amount of time as for humans. When born, the ligaments that connect the front spine to the rear are too long to hold the front body up. The ligaments will not grow as fast as the child. It will develop at the same rate a human would. At first, it will crawl on all six limbs; hands, front knees, rear feet, holding its rear end up. Then its front legs will develop the strength to hold it up on their own. After that the front body will be held up so it can walk on four legs.