The Chimera Ant Queen, or The Queen for short, is the overarching antagonist of the Chimera Ant Arc of the Hunter x Hunter series. She is the late matriarch and former ruler of the entire Chimera Ant race (or at least the ones encountered within the Chimera Ant Arc and beyond) and the mother of Meruem. Her ultimate goal is to give birth to the king and spread the Chimera Ant biome across the known world.
How she was created or where exactly she came from is completely unknown, except for the fact that she washed up injured on the shores of the Neo-Green Life Autonomous Region of the Mitene Union. There, she quickly got to work to consume as much biomass as she needed to form a proper army, eventually giving birth to numerous powerful (albeit mindless) soldiers that invaded and abducted countless humans from nearby villages to be brought to and consumed by the Queen. From that, she gave birth to the first fully-sentient Chimera Ants, which caused her to develop an appetite for consuming humans, believing them to be the key ingredient she needed to give birth to the King. The Chimera Ants quickly multiplied and spread across the technology-free nation, continuing the mass-abduction of humans to feed the Queen to further develop the Chimera Ant population.
After her appetite for humans becomes ravenous to the point of consuming 250 humans a day, she hatches all three Royal Guards, personally giving them their names. A week later, the king, still within the Queen's womb, grows tired of waiting to be born and forces his way out, critically wounding the queen and exposing her organs, rendering her infertile.
With her role as queen fulfilled, many Chimera Ants decide to leave the nest and become rulers of their own broods, with those still loyal to the dying queen staying. After the Hunter Association located her, they attempt to save her life with the aid of Dr. Lee ultimately to no avail. Before dying, she proclaims her desire to have her son fulfill his biological mission of standing atop all life.