Triton is the eldest of two sons born to the Inhuman priest and philosopher Mander and his wife, Azur. Triton was exposed to the mutagenic Terrigen Mist when he was a year old and emerged with a number of aquatic mutations. No longer able to breathe air, the young Triton was raised in a specially designed alcove on the shore of the island of Attilan. Triton's mother, a biologist, undertook the study of ocean life so she could better understand and care for her son. Eventually, a cumbersome breathing apparatus was designed to enable Triton to survive out of water for extended periods. This apparatus was refined and miniaturized by Maximus some years later.
Triton's mother died during an undersea mishap when he was 14. At 18, he became a scout for the Inhumans, keeping watch over human oceangoing traffic in the vicinity.