This is the why the Hive are the way they are

[Platypus20]

Before the Hive became the Hive, they were a species called "Krill". They were a prey species who believed they were doomed to die.

There's an ancient parasitic species of space worm.

The Krill let this worm live inside them, and it gave them abilities.

For the worm to survive, it must be fed tributes by killing things.

If a Hive creature doesn't feed their worm, the worm eats them. This might be why you see some worms wandering around.

Each Hive creature starts as a Thrall.

When a Thrall feeds its worm enough kills, the Thrall evolves into an Acolyte, and so forth (ogres are a bit different because ogres are from Wizards experimenting on a Thrall).

The Hive's desire is to become the predator of all living things so they don't feel doomed.

Thrall - Gain "tribute" through killing to grow or evolve.
Acolyte - Gain "tribute" through killing to evolve.
Knight/Wizard - Gain "tribute" through killing to evolve.
Ogre - Kill for their master (this grants extra kills for the Wizard to evolve).
Ascendant Hive - Gain "tribute" through devastation.
God-King - Gain "tribute" through the devastation of kingdoms, empires, and nations.
Worm God - Be fed through their worshippers (Be kept alive by Hive).

God-Kings have enough power to create a different a plain of existence. In their alternate plain, they can make a Throne Room. If they die in the normal world they reincarnate in their Throne Room. The only way to kill a God-King is by killing it in its Throne Room.

[AloofHermit37]

the hive are badass, thats why my clan is called Guardians of the Sword Logic and my avatar is Crota

[Kylito]

I remember first reading the Grimoire Anthology book for the Hive, it was crazy to learn about the origins. The Destiny lore is so much deeper than what is presented in-game.