Adamantoise (Final Fantasy XV)

Adamantoise is an enemy in Final Fantasy XV fought during the Lonely Rumblings in Longwythe Hunt. Defeating the Adamantoise gives the Tortoise Toppler achievement/trophy.

In order to find the Adamantoise, the player must finish the game and then take the Let Sleeping Mountains Lie quest from Cindy at the Hammerhead station. The quest concludes with the party discovering that the mountain at Longwythe Peak is actually the Adamantoise, which they then flee from. After this, the player can accept the Lonely Rumblings in Longwhythe hunt from Takka at his restaurant by the Hammerhead.

Battle
Adamantoise takes an extremely long time to kill, due to its 5,620,400 HP. Before the game had released, Tabata had mentioned 30 in-game days, which would be close to 15 hours in real time. However, in the actual game, the fight takes most players roughly 2 hours, or 3 in-game days. The good news is that its attack patterns are very predictable due to its size and it glows yellow right before it attacks. As long as the player avoids using greatswords, they should be able to take it down easily.

Etymology
Adamantoise is a portmanteau of "adamantite" and "tortoise".