Achilles is a human/Asgardian hybrid, providing him various advantages over other humans.

Superhuman Strength: Due to his Asgardian heritage he has superhuman strength.
Superhuman Stamina: His musculature generates considerably less fatigue toxins during physical activity than the musculature of a human.
Dense Tissue: Due to his Asgardian heritage his bodily tissues have about 3 times the density of the bodily tissues of a human.
Invulnerability: Achilles is uniquely indestructible, even among his relatives and other Asgardians. He has proven impervious to nearly every known form of attack or force. He can withstand great impact forces, falls from great heights, powerful energy blasts, and exposure to extremes in both temperature and pressures without sustaining injury.
Extended Longevity: Due to his Asgardian heritage he ages much slower then an average person. He is also immune to all known Earthly diseases and infections.
Regenerative Healing Factor: If he is injured, his Asgardian metabolism enables him to repair damages tissue much faster and much more extensively than a human being. However, he can't regenerate severed limbs or missing organs

Formerly Pantheon (Earth-616)

Often, he wears a personal combat suit made of an unknown metal, increasing his strength.

Formerly The Mount, Arizona; Germany; Dachau Camp

Peter David, Dale Keown

Agamemnon (ancestor);
Unnamed wife (deceased);
Unnamed son (deceased);
Unnamed daughter (deceased);
Unnamed daughter (deceased);
Unnamed foster parents;
Ajax, Atalanta, Cassiopeia, Delphi, Hector, Jason, Paris, Perseus, Ulysses, Prometheus (unspecified relatives)