Nexus: A powerful creature that answers to no other being and directs the swarm, it gives the swarm meaning and purpose, their goals become the goals of the entire swarm without question or complaint. While the Nexus is powerful they are not able to control every part of the swarm at all times, and as the swarm grows larger it becomes more difficult to do so over greater distances. Thus, the creation of warlords and advisors...

Leaders are drones or infested creatures intellectually enhanced in order to take command over parts of the swarm in order to increase the efficiency of the Nexus. The Leaders control other lesser drones and follow the orders of the Nexus.

Warlords: A monster designed to tactically lead the swarm from the front lines and devastate the battlefield, carrying out the will of the Nexus. It is designed to aid the Nexus in guiding the swarm as the pure manifestation of its wrath. Whenever the swarm grows to such a size or when the swarm needs to travel beyond the direct influence of the Hivemind, the Nexus creates Warlords to control the drones remotely as they break away from the main mass.

Brood Keepers/Advisors (WIP): The Scientists/Magic users of the swarm. They keep the templates of each swarm creature, including variations and mutations, and use the spawning pools to produce drones as if off of a factory line. Once the Brood Keepers have access to a spawning pool, the swarm will have a near endless supply of drones. They are creatures designed as a strategist and defensive leader. While the Warlords are tasked with conquering and capturing, the Keepers act as lords and regents. After the Warlord takes a position the Keepers are charged with keeping it. They lead Worker Drones and defensive Warrior Drones to dig in, build, set up spawning pools, and provide support and assistance to the swarm from an entrenched position.

Elites: These are the beings of the swarm that serve as an even more focused aspect in the chain of command. Just as the Warlords are to the Queen, the Elites are the great warriors under the Warlords that command small strike forces for specialized missions. They are the Marines of the swarm, uniquely evolved for special missions and operations.

Pilgrims: These are swarm organisms designed to infiltrate other societies without immediately being recognized. They are the spies and infiltrators, as well as ambassadors and interrogators. They are given an inordinate amount of Independence from the hivemind, given that they are often too far away from the collective while on their missions abroad to receive constant guidance from the Hierarch.

Warrior Drones: Creatures evolved to hunt, kill, and survive. Some are mutated to be brutish warriors, some are evolved into fleet-footed scouts, others are designed for defense or siege breaking. They are the swarm.

Worker Drones: Workers, builders, miners, harvesters, creatures who are evolved less for combat and more to build immense structures and hives for the swarm, harvest raw materials and resources and utilize them towards the formation of hive structures and weapons. They are the swarm.

Tool Drones: These are organisms in the shape of weapons, creatures forged for a specific purpose. They are the constructs that the larva turn into, they are the weapons the Elites hold. They are a wide generalization of creatures, but in essence, they are living technology for the swarm.

Nexus:
Havilah - The Queen of Resurgence

Advisors: 20
Warlords: 20
Brakka - General of the Swarm

Elites: 100
Scabbers
Kony
Aethiri
Behemoth Cast: 1,000
Leviathan Cast: 10
Warrior Cast: 100,000
Worker Cast: 1,000,000

Other smaller swarms fall under the hierarchy of the Sovereign Swarm, answerable to the queen and no other:
The Swarm of Harvest
The Swarm of the Damned

Brood: a generation of young Cast, produced at one hatching.
"a brood of chicks"

Cast: a creature made by shaping biomass or genetic strands in a template.
"bronze casts of the sculpture"

Colony: a community of Cast living close together or forming a physically connected structure.
"a colony of seals"

Drone: a Cast creature adhering to a common template in a swarm or colony of Cast, which exclusively responds only to a hierarch.

Genetic Code: the nucleotide triplets of DNA and RNA molecules that carry genetic information in living cells.

Genetic Strands: a nucleic acid that carries the genetic information in cells and some viruses, consisting of two long chains of nucleotides twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine and thymine or cytosine and guanine. DNA sequences are replicated by the cell prior to cell division and may include genes, intergenic spacers, and regions that bind to regulatory proteins.

Genetic Material: any material of plant, animal, microbial or other origin that carries genetic information and that passes it from one generation to the next. The information contained controls reproduction, development, behaviour, etc.

Hierarch: a chief priest, archbishop, queen, nexus, or other leader.

Hivemind: A unified consciousness or intelligence formed by a number of Cast individuals, the resulting consciousness typically exerting control over its constituent members.
"there is a Queen who controls the hive mind"

Nexus: a connection or series of connections linking two or more creatures.
"the nexus between industry and political power"
the central and most important point or place.
"the nexus of all this activity was the disco"

Swarm: A large or dense group of Cast.
"a swarm of locusts"

Queen: a reproductive or authoritative female in a colony of Cast creatures.