The Bicolor-spined Porcupine is a nocturnal mammal native to the rainforests of Colombia, Ecuador, Peru, and Venezuela. It has a dense coat of yellow-based, black-tipped spines that darken on its mid-back. Its primarily spine-free tail is fully prehensile, aiding in maneuverability.

It communicates using various sounds and primarily feeds on leaves, fruits, and bark, supplementing its diet with roots, stems, and insects. 

After a gestation period of around 200 days, the female gives birth to a single offspring, which initially has soft quills that harden within a few days.

Long-tailed porcupines, indigenous to regions such as Brunei, Indonesia, and Malaysia, resemble rats. They boast black or brown coloration, contrasting with white underbodies. Short, dark brown spines with white bases blanket their bodies, excluding their heads and underbelly.

Among their defensive mechanisms, they shed their tails when seized by predators, but these tails do not regenerate. Their broad paws enable adept tree climbing, which is useful when foraging for food. 

Primarily herbivores, they consume various plant materials, including leaves, wood, roots, and bark. Occasionally, they also ingest insects and other arthropods. Notably, their role as food hoarders aids in seed dispersal.

The North African Crested Porcupine is one of the largest rodents in the world. Its black or brown body is covered with porcupine quills that can reach up to 14 inches. It prefers rocky terrain, where it spends most of the day in complex burrows. 

While generally peaceful, the Crested Porcupine will fight back when it perceives an immediate threat.

The Indian Crested Porcupine is a nocturnal mammal in southern Asia and the Middle East. It has long, thin quills on its head and back, which it raises when threatened. Moreover, it can adapt well to various environments, including rocky hillsides and sandy deserts.

During the day, the Indian Crested Porcupine stays in its burrow. Then, it ventures out at night to forage. The porcupine feeds on roots, fruits, and crops. It also gathers bones to supplement its diet with essential minerals.

A study on Indian Crested Porcupine's quills reveals the development of antibacterial keratin microparticles1. These microparticles enhance pharmacological action against harmful bacteria, like Escherichia coli and Staphylococcus aureus, showing up to a 55% improvement when coated with lipids from the same quills. This groundbreaking study demonstrates potential use in clinical applications.

The Malayan Porcupine lives in the dense forests of Southeast Asia. During the day, it hides in the root networks of trees, termite mounds, or rocky crevices. At night, it emerges to feed on roots, bark, and fallen fruits. 

Moreover, the Malayan Porcupine's most distinctive feature is its coat of sharp, dark quills that stand on end when it senses danger. It also occasionally preys on insects or small vertebrates.

The Cape Porcupine has black quills with white or yellowish stripes, a crucial defense mechanism. It lives in a wide range of habitats across Africa. 

While primarily an herbivore, Cape Porcupines also gnaw on bones to supplement their diet with calcium. They are also good swimmers and climbers.

The Philippine porcupine, also known as the Palawan porcupine, is a distinctive creature native to the island of Palawan in the Philippines. Its habitat is commonly a blend of secondary forest and grassland, with some residing in lowland primary and secondary forests. 

IUCN gave Philippine Porcupines vulnerable status2. Over the coming 22 years, its population is projected to decrease by more than 30%. Forest loss and its rampant use in pet and bushmeat trade are significant factors accelerating this decline.

The African brush-tailed porcupine  (Atherurus africanus) is a species of rat-like Old World porcupine, indigenous to a broad belt of Africa ranging from Guinea on the west coast to Kenya on the east. This is a common species with a very wide range, and despite it being used extensively for bushmeat, the International Union for Conservation of Nature  has rated its conservation status as being of "least concern".[1]

The American Eel lives in the far-flung corners of the North Atlantic. It has a snakelike body and can grow up to five feet, though most individuals measure only two to three feet. 

Its skin ranges from yellow to green-brown, and it has a lighter belly, camouflaging it in riverbeds and coastal waters.

These types of eels are both freshwater and saltwater eels. They spend most of their lives in freshwater or brackish environments. However, during the breeding season, they migrate to the ocean. 

Additionally, these true eels eat various prey, such as insects, crustaceans, and fish. At night, the American eel emerges from the sand to hunt. They also don’t hesitate to step onto land for food.

The European Eel can grow up to 5 feet long and camouflage itself in its environment. Moreover, they are nocturnal hunters that feed on insects, crustaceans, mollusks, and other small aquatic animals.

Additionally, European Eels are catadromous; they spend most of their lives in freshwater or brackish waters and travel to the Sargasso Sea to breed1. 

They turn from larvae to glass eels during their journey, then to yellow and silver eels. These types of eels can also breathe through their skin, enabling them to survive short periods of drought.