Sub-Mariner
Prince Namor is the half-human/half-Atlantean ruler of Atlantis.
Triton
Triton is a member of the Inhumans.
Attuma
Attuma was born into the tribe of Homo mermanus who eschewed civilization to live as nomadic barbarians. For some unrecorded reason, Attuma was endowed with strength far surpassing that of his people.