Goblinoids

Goblinoids are strange creatures. They're essentially one species with many races. Any goblinoid can innately recognize another creature as a goblinoid, even if it's a completely different race of goblinoid. With this innate recognition comes an understanding of hierarchy, and the goblinoids will immediately understand who is above whom. The goblinoid lower in the hierarchy will instinctively follow the other goblinoid's orders.
Although different in size, shape, skin tones, and personality traits, one thing all goblins have in common is a level of sadism seen in few intelligent creatures.

The Goblinoid Races

Uri Goblin

Uri goblins are small, green skinned with red, orange, yellow, or black eyes in their oversized heads. They're highly chaotic creatures with little to no empathy, and tend to do whatever it is that brings them joy. Very often this is seeing others hurt in some way, but it could also be something as simple as dressing up or spinning around in a circle to get dizzy.
(Template: Goblin, Pathfinder)

Kirisute Goblin

The equally small Kirisute goblins are less chaotic than their Uri cousins, but only to the point where they seem more dangerous than absurd. Their skin tones ranges on the red to yellow spectrum, and the colours of their eyes are red, orange, yellow, or black. They're militaristic, and although not very strong, they can be highly dangerous in large groups.
(Template: Goblin, D&D)

Oni Goblin

Oni Goblins are feral goblins with red skin, sharp claws, and nose horns. Despite perhaps being the least intelligent of all goblinoids, they aren't as chaotic or spontaneous as their Uri and Krisute cousines, but are much more viscious!
(Template: Dekanter goblin)

Kinkotsu Goblin

While Kirisute and Uri goblins are about the height of halflings and gnomes, Kinkotsu goblins stand about a head taller, closer to the height of a dwarf. And similarly to a dwarf, they have a broad, stout, and compact build. Their skin tone is usually green, sometimes with a bit of yellow in it. They tend to be quite serious, like Taisa goblins. They're not as quick to violence as their smaller cousins, but from the eyes of most other species, the difference is minimal.
(Template: None)

Taisa Goblin

Looking like man sized Kirisute goblins in every aspect, Taisa goblins are extremely militaristic creatures. They're much more focused, and much less chaotic. While other goblinoids might use weapons, Taisa spend much of their free time training to become masters of them. They're also smart and good at combat tactics. Taisa goblins live for war and violence. Though they're usually encountered in warbands or armies, they're also deadly alone.
The Taisa are the highest ranking goblinoid. Any other goblinoid will instinctively follow the commands of a Taisa goblin. Many believe they are the original goblinoid, and that all other goblinoids have been bred for specific uses in battle. A single Taisa can walk into a random village of Kirisute goblins, and every single goblin in that village will immediately begin following the Taisa's orders, even if it'll kill them.
(Template: Hobgoblin)

Yajuu Goblin

The Yajuu Goblin is the largest of the goblinoids, standing a whole head taller than a human or Taisa. Unlike other goblinoids, they have a thick coat of yellow fur. Although relatively intelligent, they're quite bestial in nature.
(Template: Bugbear)

Goblinoid Hierarchy

The following table lists all goblinoids in their hierarchal structure, with the hhghest ranking goblinoid race on top, and the lowest ranking goblinoid race at the bottom.

Goblinoid Hierarchy
Taisa Goblin
Yajuu Goblin
Kinkotsu Goblin
Kirisute Goblin
Uri Goblin

Reproduction

Most goblinoids do not breed true, only Taisa goblins, whom have a reproduction system similar to that of humans. As such, the other types of goblinoids usually don't have genitalia or other means of reproduction. And while Taisa goblins have binary sexes, most other goblinoids are sexless, though they might have gender identities. In rare cases, mutations may occur that might cause a goblin to have physical traits more akin to one of the binary sexes of the Taisa.
Other goblinoids are actually created by Taisa goblins, sometimes on purpose, other times accidentally: Spilling the blood of a Taisa goblin on fertile soil will cause eggsacks to grow there, which will eventually hatch into Uri goblins. The eggsacks are green and translucent, and the Uri goblin hatchling grows to maturity within only a couple of weeks.
Kirisute goblins are grown on fertile soil through a mixture of blood and saliva, and their eggsacks have a orange hue, but are otherwise very similar to Uri goblins.
Oni goblins are grown from the teeth of the Taisa, and take much longer to grow. Because of this, the growing Oni goblin eggsack is often destroyed by the surrounding nature it grows in. They usually take a month to grow, and their eggsacks have a blood red hue to them. They're fully adult from the moment they hatch, however.
Kinkotsu goblins are born from the gastric system of the Taisa, and mainly come to be through a Taisa dying of a gut wound. Their eggsacks are a mossy green colour, and take about two weeks to hatch the Kinkotsu goblin.
The Yajuu are born from a mixture of Taisa blood, sweat, and hair. A weaker Taisa is often tortured for the ingredients to make this goblinoid brute. Their eggsacks are a brown colour, and they take about a month to hatch, reaching adulthood about a week afterwards.