- A nefarious fiend told of in legends, its brutality far surpassing that of other deathclaw. Its name is recorded in lost pages of the Cosmogony as one of the creatures that fought to a standstill against the twenty-four Messengers in the kingdom's nascent years. The return of naglfar is said to be an omen of unspeakable disaster to come.
- Size: 48.85 ft. Weight: 22.75 t
The English bestiary says naglfar's name is recorded in the "lost pages" of the Cosmogony, and that it fought the 24 Messengers to a standstill in the early days of Lucis. The Japanese version says its name is recorded in the pseudepigrapha of the Cosmogony. Pseudepigrapha means falsely-attributed works, texts whose claimed author is not the true author, or a work whose real author attributed it to a figure of the past.
Naglfar resists all weapon types, but is weak to all elements. Naglfar's attacks can do immense damage to even a level 99 party (upwards of 7000+ damage). It uses both physical and magical attacks and employs Dark-elemental attacks. There is a point-warp spot on the battlefield where the player can warp to replenish MP and health. Like its two weaker family members, many of its attacks can't be phased through, so manually dodge-rolling with good timing is advised. It uses laser attacks that travel in straightforward lines.
The player should focus on creating the best Elemancy spells (Flare, Freeze, Electon). By creating spells with Zu Beaks, the player can create multiple spells which break the damage limit. The player should equip weaponry and eat food that boost Noctis's Magic (Tenebraen Berry Opera that becomes available at Galdin Quay after bringing Coctura Arlund berries obtained from the Cape Caem farm trade gives +500 to Magic at the cost of knocking Strength down to 0). Using the best Elemancy spells against the Naglfar can deal 99,999 damage, meaning that it can be defeated with ten spells, fewer if the player summons during the battle. The player can also poison it by adding the corresponding catalysts to Elemancy.
The player should be prepared to dodge multiple times between castings, and have Hi-Elixirs ready when Noctis goes down (or Megalixirs and Mega Phoenixes if the player intends to keep the entire party alive).
Another strategy is to use the Star of the Rogue with Ignis imbuing it with all three elements via the Enhancement Technique. The player can eat food that adds Equalizer if the level gap is considerable: Spicy Skewers at Lestallum and Seasoned Midgardsormr at camp. The player should use an ally Technique when naglfar is about to do one of its undodgeable attacks. The player can warp-strike and use the point-warp spot to replenish MP, and use Armiger/Armiger Unleashed and summons when they become available.
Naglfar can be killed instantly with Alterna if the player gets lucky.
In Norse mythology, Naglfar is a boat made entirely from the fingernails and toenails of the dead.
- The Squirming Bone key item Naglfar yields is the only "monster part" obtained from a daemon. Usually only biological monsters drop monster parts, whereas daemons dissolve into miasma upon being defeated. The description to Squirming Bone describes it as "the partial remains of a deathclaw, still wriggling with life."