The Knight Anole, or Anolis equestris, is a large lizard native to Cuba, although it has been introduced to parts of Florida. It can grow up to 50 cm in length, including the tail, and is known for its bright green color, which can vary depending on its mood or environment. This arboreal lizard prefers humid tropical forests where it primarily feeds on insects, small birds, and fruits. It has a broad head and mobile eyes, allowing for effective peripheral vision. Males have a prominent dewlap used to impress females or intimidate rivals.

The king cobra is a large venomous snake in the family Elapidae, reaching 3–4 m in length, with olive-brown body and a lighter dorsal hood. It inhabits tropical forests, mangroves and wetlands, feeding mainly on other snakes, small mammals and birds. During breeding season, males engage in ritual combat and females build a leaf nest to lay 21–40 eggs.

The Kirk's Dik-dik is a small antelope, recognizable by its modest size and distinctive features, including its elongated snout and large, expressive eyes. Standing about 40 cm tall at the withers and weighing between 3 and 6 kg, it is one of the smallest members of the antelope family. Its coat is usually light brown or gray, with a paler belly and distinct facial markings. The Kirk's Dik-dik primarily inhabits savannas and wooded areas in East Africa, notably in Somalia, Kenya, Tanzania, and Ethiopia. It feeds mainly on leaves, fruits, and herbaceous plants. This small herbivore is mostly active at dusk and during the night, using its well-developed sense of smell to detect predators, emitting a characteristic call to alert other members of its group. The Kirk's Dik-dik is typically solitary or lives in small family groups. Although it is not currently threatened, it faces dangers such as habitat loss due to agricultural expansion and hunting.

The Komodo Dragon is a large carnivorous lizard, famous for its impressive size and strength. It typically measures between 2 and 3 meters in length and can weigh up to 70 kg. Its massive body is covered with scales, usually grayish-green, which helps it blend into its natural environment. The Komodo Dragon is found exclusively on a few islands in Indonesia, including Komodo, Rinca, Flores, and Gili Motang. This apex predator feeds on a variety of animals, from birds to mammals like deer, as well as carrion. It primarily hunts using its developed sense of smell, able to detect odors from several kilometers away. Due to its powerful bite and saliva filled with bacteria, the Komodo Dragon can incapacitate its prey and wait for it to succumb to infection before feeding. The species is listed as vulnerable, threatened by habitat loss, illegal hunting, and excessive tourism. Conservation efforts are in place to protect this unique creature and its habitat.

The Kestrel is a small raptor from the falcon family, easily recognizable by its light brown plumage and dark spots that adorn its back. It measures about 30 to 35 cm in length, with a wingspan of 70 to 80 cm, and weighs between 150 and 200 g. The adult male has more colorful plumage, with shades of gray and black bands on the tail, while the female has a duller, brownish plumage. This falcon is common throughout Europe, Asia, and North Africa, where it primarily inhabits fields, meadows, heathlands, and even urban areas. The Kestrel feeds mainly on small mammals, insects, reptiles, and sometimes smaller birds. It is especially known for its hovering flight technique, where it remains suspended in the air by rapidly beating its wings before diving to capture prey. While the species is not currently endangered, it faces threats such as habitat loss, reduced prey populations, and disruption by human activities.

The Kakapo is a nocturnal and terrestrial parrot, easily recognizable by its moss-green plumage and large wings, although this bird cannot fly. It measures about 60 cm in length and weighs between 2 and 4 kg, making it the heaviest parrot. Its plumage is mainly green, with yellow and brown hues that help it blend into its natural environment. The Kakapo is found exclusively in New Zealand, where it prefers dense forests and mountainous areas. It is herbivorous and feeds on plants, fruits, seeds, and roots. Due to its inability to fly, it has developed excellent climbing skills and primarily moves by walking. The species has been severely threatened over the centuries by predation from introduced mammals and habitat loss. Today, the Kakapo is an extremely rare and critically endangered bird, with intense conservation efforts focused on protecting the remaining individuals.

The Kangaroo is an iconic marsupial, famous for its large size, powerful hind legs, and long tail. It typically measures between 1 and 1.8 meters in length, with a tail length of 80 to 100 cm, and can weigh between 18 and 90 kg, depending on the species. Its coat varies depending on the species but is generally gray or red, with dense fur that protects it from the extreme temperatures of Australia. The Kangaroo is an excellent jumper, capable of covering large distances with its powerful hind legs and its tail, which serves as a counterbalance when it moves. Herbivorous, it primarily feeds on grass, leaves, and young shoots. Kangaroos primarily inhabit open plains, forests, and savannahs in Australia. They are social animals, often living in groups called "mobs," although they can also be solitary. While the species is not endangered, it is sometimes threatened by habitat loss, bushfires, and competition with livestock.

The Kea is a large parrot endemic to New Zealand, easily recognizable by its bright green plumage and reddish-edged feathers on its neck and under its wings. It measures about 48 cm in length and weighs between 800 and 1,200 g. This parrot is one of the most intelligent of its kind, capable of using tools to solve complex problems and adapt to a variety of environments. The Kea is omnivorous and opportunistic, feeding on fruits, roots, seeds, small animals, as well as carcasses of dead animals. It is particularly known for its curious and sometimes destructive behavior, earning it a reputation as a "thief" in some areas. The Kea primarily inhabits the alpine mountains of the South Island of New Zealand, where it resides at high altitudes. While the species is protected, it remains vulnerable to habitat loss and human threats such as trapping and vehicle collisions. The Kea population has declined over the years, but conservation efforts are underway to ensure its survival.

The Kiwi is a bird endemic to New Zealand, famous for its brown, fluffy plumage, small size, and long straight bill. It measures about 40 to 50 cm in height, with a wingspan of 60 to 80 cm, and weighs between 1 and 4 kg depending on the species. The Kiwi is one of the most distinctive birds in the world due to its unique appearance: it has small wings that do not allow it to fly, a long delicate nose, and short legs adapted for its terrestrial life. It primarily inhabits the forests, woods, and grasslands of New Zealand, where it feeds on earthworms, insects, fruits, and roots. The Kiwi is a nocturnal bird, feeding primarily at night and being particularly vulnerable to introduced predators such as rats, mustelids, and dogs. It is also threatened by the loss of its natural habitat, and several species of Kiwi are critically endangered. Active conservation, such as nest protection and predator elimination, is essential to ensure the survival of these iconic birds.

The Koala is an iconic tree-dwelling marsupial from Australia, easily recognizable by its grey-silver fur, large round ears, and heart-shaped black nose. It measures about 60 to 85 cm in length and weighs between 4 and 15 kg, with males generally being larger than females. The Koala has powerful claws adapted for its tree-dwelling lifestyle, spending almost its entire life in trees and feeding primarily on eucalyptus leaves. Its diet is very specific, and while eucalyptus is an abundant food source, it is also toxic to most other animals, providing the Koala with some degree of protection from predators. The Koala is a nocturnal and solitary animal, spending the majority of the day sleeping in trees, seeking refuge in Australia's forested areas. It is a symbol of Australian wildlife, but its habitat is threatened by deforestation, bushfires, and disease, which has led to a decline in its population. Conservation efforts are underway to protect this marsupial and its natural habitat.

The King penguin is the second largest species of penguin, after the emperor penguin. It primarily lives on subantarctic islands and the coasts of Antarctica. This penguin is easily recognizable by its distinctive black and white plumage and its bright orange coloring on the sides of the head and neck. It primarily feeds on fish, krill, and squid, which it captures by diving into the water. The King penguin is a social species, living in dense colonies, and is known for its spectacular courtship displays.

The Houtouc Motmot is a colorful and fascinating bird, primarily found in the tropical forests of Central and South America, notably in Costa Rica, Panama, and Colombia. It measures about 40 cm in length and is easily recognized by its vibrant plumage, often dominated by shades of blue, green, and orange. What particularly distinguishes this bird are its tail feathers, which are long and feature a characteristic fan at the tips. The Houtouc Motmot is a small predator, feeding primarily on insects, small reptiles, and sometimes fruits. It is often seen perched on low branches, where it watches its surroundings in search of prey before diving quickly to catch it. Although often solitary or in small families, it emits a piercing call to signal its presence. The species is not currently endangered, but it is sometimes threatened by deforestation and the loss of its natural habitat.

The Kermode Bear, also known as the "spirit bear" or "white-furred bear," is a rare subspecies of the American Black Bear. It measures between 1.2 and 1.8 meters in length and weighs between 70 and 250 kg. What particularly distinguishes the Kermode Bear is its coat, which can vary from black to creamy white, although the majority of these bears have black fur. This subspecies primarily lives in the humid forests of British Columbia, Canada, and feeds mainly on fruits, berries, fish, and small mammals. The Kermode Bear is typically solitary and inhabits remote areas. Although it is relatively rare, it is not considered to be in immediate danger, though it faces threats from habitat loss and other human-related activities.

The Keel-billed Toucan is a large, colorful bird found primarily in the tropical forests of Central America, notably in Costa Rica, Guatemala, Honduras, and Mexico. It typically measures about 50 cm in length and weighs between 400 and 500 g. Its plumage is mainly black, with a bright yellow chest and face, and it is easily recognizable by its large, colorful bill, which is primarily orange with shades of red and yellow. The Keel-billed Toucan primarily feeds on fruits, berries, and nuts, but can also consume insects and small reptiles. It generally lives in social groups and is an excellent climber, spending much of its time in trees. While its population remains relatively stable, the Keel-billed Toucan is sometimes threatened by habitat loss due to deforestation.