Chimera Ants

The Chimera Ants are a species of ants that can take on the trains of other species. While most are the size of normal ants, a breed of giant ants, originating from the Dark Continent, serve as the main antagonists of the Chimera Ant arc of Hunter x Hunter. While initially portrayed as vicious monsters, many of the ants are shown to be more sympathetic, and many are redeemed throughout the story, while the humans become more monstrous.

Normal Chimera Ants
The queen appears as a normal ant. As she eats other speces, she gives birth to children who have traits of other species in a process called Phagogenesis. The children are soldier ants who initally serve the queen. Eventually, the queen will give birth to royal guards, and then to one or multiple kings, who will mate and sire a new queen.

In the Story
The queen in the story was a giant ant from the Dark Continent. She was intelligent, though she could not speak normally. She was able to speak telepathically to her children. Eventually she discovered that eating humans produced strong and intelligent children. Humans became the primary diet of the queen and other ants, and the children all had human like traits and the ability to speak. Chimera Ants often had memories of the humans used to create them.

The Chimera Ants discovered that some humans had the mystical ability of Nen, which made them stronger. After this, most of the chimera ants learned Nen, an tried to feed human Nen users to the queen. The three royal guards, as well as the king, were born as Nen, and were much more powerful than the rest of the ants. The royal guard Shaiapouf was able to use Nen to turn humans into Chimera Ants.

Story
The queen inhabited a reclusive country called the NGL. She reproduced and created soldier ants. She eventually ate two human children, and discovered that Chimera Ants produced from children had the ability to speak. She ordered her soldiers to capture humans from the NGL to consume. The Hunter association was sent to deal with the Chimera Ants. Many of the Chimera Ants ended up learning Nen, and became more powerful. The three royal guards were born learning Nen, and were much more powerful than the rest. Eventually, the queen gave birth to the King, but she died shortly after birthing him. She called him Meruem, though he would not learn his name until later. Meruem was shown to be ruthless even to the other ants, and he left with his royal guards to conquer the Republic of East Gorteau.

After the king left, most of the Chimera Ants spread and tried to become kings of their own. None were successful, and those that weren't killed later joined Meruem. A few ants helped the main characters fight against the king. The king and his royal guards had a plan to kill most of the citizens of East Gorteau, and those few who could use Nen would be turned into Chimera Ants in service to the King. Several hunters were dispatched in order to stop the king and his army.

The King ended up meeting a human girl named Komugi, and developed a close relationship with her. He ended up more sympathetic towards humans. The hunters ended up attacking the palace in East Gorteau in order to seperate the royal guards from the king. The Chairman of the Hunter Association, Isaac Netero, battled the king. Netero was defeated, but before he died, told the king what his mother had named him. As Netero died, a bomb inside him called Miniature Rose exploded. The King was severely injured, though his royal guards saved him. The king lost his memories and became more powerful, although he eventually regained his memories. The Miniature Rose was poisoned, similar to how a nuclear bomb causes radiation poisoning. Meruem along with two of the royal guards were killed by the poison. Meruem died alongside Komugi.

The hunters killed many of the Chimera Ants, and those that survived after the death of the king were put under the control of the Hunter Association.

Trivia

 * Many of the Chimera Ants undergo antiparallel character arcs to the human characters. For example, Meruem becomes more sympathetic and kind, while the main hero, Gon becomes more viscious and cruel as the story progresses.