Who killed the King in Hunter X Hunter?

Right after Meruem aka King finished his fight against Netero, he ended up getting poisoned and faced death.

The 10 Best 'Hunter X Hunter' Villains, Ranked

Art of Hunter x Hunter

Meruem, Hunterpedia

The 10 Best 'Hunter X Hunter' Villains, Ranked

Hunter X Hunter – 396-397 - Lost in Anime

Explaining Hunter x Hunter's Chimera Ant arc is a rite of passage - Polygon

Hunter X Hunter 2011 - 131 - Lost in Anime

Hunter x Hunter Episode 134

Will Meruem Die in Hunter x Hunter? Meruem's Death in HxH - OtakuKart