The Kaldanes are a fictitious sapient species existing in the region of Bantoom on the planet Barsoom

Barsoom

Barsoom is a fictional representation of the planet Mars created by American pulp fiction author Edgar Rice Burroughs, who wrote close to 100 action adventure stories in various genres in the first half of the 20th century, and is now best known as the creator of the character Tarzan...

 (i.e. Mars

Mars

Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

) in the John Carter

John Carter (character)

John Carter is a fictional character, created by Edgar Rice Burroughs, who appears in the Barsoom series of novels. Though actually a Virginian from Earth and a visitor to Mars, he is often referred to as "John Carter of Mars" in reference to the general setting in which his deeds are recorded, in...

 series of books by Edgar Rice Burroughs

Edgar Rice Burroughs

Edgar Rice Burroughs was an American author, best known for his creation of the jungle hero Tarzan and the heroic Mars adventurer John Carter, although he produced works in many genres.-Biography:...

. Introduced in the book Chessmen of Mars, the Kaldanes are almost all head, but for six arachnoid legs and a pair of chelae. Their racial goal is to evolve further towards pure intellect and away from bodily existence:

"It is only your brain that makes you superior to the banth, but your brain

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

 is bound by the limitations of your body. Not so, ours. With us brain is everything. Ninety per centum of our volume is brain. We have only the simplest of vital organs and they are very small for they do not have to assist in the support of a complicated system of nerves, muscles, flesh and bone. We have no lungs, for we do not require air. Far below the levels to which we can take the rykors is a vast network of burrows where the real life of the kaldane is lived. There the air-breathing rykor would perish as you would perish. There we have stored vast quantities of food in hermetically sealed chambers. It will last forever. Far beneath the surface is water that will flow for countless ages after the surface water is exhausted. We are preparing for the time we know must come -- the time when the last vestige of the Barsoomian atmosphere is spent -- when the waters and food are gone. For this purpose were we created, that there might not perish from the planet Nature's divinest creation -- the perfect brain."

In order to function in the physical realm, the Kaldanes have bred the Rykors, a nonsentient complementary species composed of a body similar to that of a Red Martian but lacking a head; when the Kaldane places itself upon the shoulders of the Rykor, a bundle of tentacle

Tentacle

A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...

s connects with the Rykor's spinal cord

Spinal cord

The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...

, allowing the brain of the Kaldane to control its motor nerves and sensory nerve

Sensory nerve

Sensory nerves are nerves that receive sensory stimuli, such as how something feels and if it is painful, smooth, rough, etc.They are made up of nerve fibers, called sensory fibers .Sensory neurons are neurons that are activated by sensory input Sensory nerves are nerves that receive sensory...

s. Should the Rykor become damaged or die, the Kaldane climbs upon another.

"Immediately I control every muscle of the rykor's body--it becomes my own, just as you direct the movement of the muscles of your body. I feel what the rykor would feel if he had a head and brain. If he is hurt, I would suffer if I remained connected with him, but the instant one of them is injured or becomes sick we desert it for another. As we could suffer the pains of their physical injuries, similarly do we enjoy the physical pleasures of the rykors."

Although the Rykors breed like other animals, the Kaldanes do not breed except for their "king":
"He produces many eggs from which we, the workers and the warriors, are hatched; and one in every thousand eggs is another king egg, from which a king is hatched. Did you notice the sealed openings in the room where you saw Luud? Sealed in each of those is another king. If one of them escaped he would fall upon Luud and try to kill him and if he succeeded we should have a new king; but there would be no difference. His name would be Luud and all would go on as before, for are we not all alike? Luud has lived a long time and has produced many kings, so he lets only a few live that there may be a successor to him when he dies. The others he kills."

The Kaldanes are also imbued with conscious race memory, obtained through selective breeding. They are carnivorous, and sometimes feed upon the Rykors.

Ghek had never seen an ulsio, since these great Martian rats had long ago disappeared from Bantoom, their flesh and blood having been greatly relished by the kaldanes; but Ghek had inherited, almost unimpaired, every memory of every ancestor, and so he knew that ulsio inhabited these lairs and that ulsio was good to eat, and he knew what ulsio looked like and what his habits were, though he had never seen him nor any picture of him. As we breed animals for the transmission of physical attributes, so the Kaldanes breed themselves for the transmission of attributes of the mind, including memory and the power of recollection, and thus have they raised what we term instinct, above the level of the threshold of the objective mind where it may be commanded and utilized by recollection.

In the Wold Newton Universe

Wold Newton family

The Wold Newton family is a literary concept derived from a form of crossover fiction developed by the science fiction writer Philip José Farmer...

, the kaldanes are mentioned as mutated Sarmaks

Martian (War of the Worlds)

The Martians, also known as the Invaders, are the fictional race of extraterrestrials from the H.G. Wells novel The War of the Worlds. They are the antagonists of the novel, and their efforts to exterminate the populace of Earth and claim the planet for themselves drive the plot and present...

 and possibly descended from Cthulhu

Cthulhu

Cthulhu is a fictional character that first appeared in the short story "The Call of Cthulhu", published in the pulp magazine Weird Tales in 1928. The character was created by writer H. P...

oids. In Larry Niven

Larry Niven

Laurence van Cott Niven / ˈlæri ˈnɪvən/ is an American science fiction author. His best-known work is Ringworld , which received Hugo, Locus, Ditmar, and Nebula awards. His work is primarily hard science fiction, using big science concepts and theoretical physics...

's Rainbow Mars

Rainbow Mars

Rainbow Mars is a science fiction short story collection by Larry Niven. It includes the five previously published Svetz stories and the novel, also called Rainbow Mars in which humans from Earth visit Mars and find it populated by the creations of Edgar Rice Burroughs, Ray Bradbury, C. S. Lewis,...

, Kaldanes also appear, although they are called the Tunnel Crabs.