The Naglfar is a ship in Norse mythology, made from the fingernails and toenails of the dead. The Argo was the ship which Jason and his crew (the Argonauts) sailed on in their quest for the Golden Fleece in Greek mythology.
A large ship with great speed and thick armor, the Naglfar forms the foundation of transport ship defenses. It was built with a focus on anti-submarine abilities to destroy hounds used for commerce raiding, generally leaving air support to a separate squadron of escort aircraft. Its Gatling-style CIWS control has been noted to have been truly exceptional.
The Faith Organization's 5th Argo-class (アルゴ級 Arugo-kyū) battlecruiser, the Naglfar was half-deified after avoiding any friendly damage while simultaneously shooting down six large anti-ship missiles skimming along the ocean surface after being fired from an enemy sub.
However, three months prior to the incident after Mariydi Whitewitch fell foul of Thor's Hammer, it fell to an aerial bombardment from Ice Squadron after its escort squadron messed up. Despite being caught like fish in a barrel, the crew from the captain down fought bravely to the end, enough that Ice Squadron had to put in overtime for free. Afterwards, it was grounded on a fjord.
Three months after its defeat, the wreck had become a home for seabirds.