Lagiacrus is a blue Leviathan that mostly dwells in the sea/deep bodies of water and comes onto beaches to sunbathe. It has a hood-like crest on its neck to aid in sunbathing. Lagiacrus is the flagship monster of Monster Hunter 3.
When a Lagiacrus is fully sunbathed, it turns a dry grayish-blue color and its dermal spikes turn a pale red, such as in the picture above. When it returns to the water, Lagiacrus regains a striking deep blue color and its spikes return to their original color of a very light beige.
The dermal spikes on its back glow white when it is using strong thunder attacks, and its mouth gurgles with Thunder when it is enraged.
Known as Sea Wyverns, Lagiacrus are at the top of the aquatic food chain. Feared by sailors as 'The Lords of the Seas', they store enough electricity in their spinal organs to make the oceans surge. Occasionally seen resting on land.
Leviathans that exist at the top of the aquatic food chain. Feared by sailors as the "Lords of the Seas", Lagiacrus store enough electricity in their spinal organs to make the oceans surge. Occasionally they can be found resting on land as well.
Lagiacrus is the first Leviathan of it's kind to be encountered in Monster Hunter 3.
Lagiacrus shares many condition with Rathalos:
Both held the title of a flagship monster.
Even though they are flagship monsters, they don't have their own theme music.
Both are weak to each other's elemental powers.
Both appear in Tri's opening movie.
Both have their subspecies appear in MH3U's opening.
Both have a subspecies that inhabits the same habitat as them and a rare species that shares habitats with Elder Dragons.
Both are the only old flagship monsters that can be fought in 3U's low ranked quests.
Breaking its dermal spikes reduces its ability to use electrical attacks.
When low on stamina, it will fail to use it's electrical charge attacks.
Hitting Lagiacrus with any kind of bomb (including Sonic Bombs and Crag/Cluster shots) underwater, may cause it to drop an item (Shiny).
A Lagiacrus either will eat an Epioth, or come up on land for air to recover Stamina - however, both often give no indication of Stamina recovery.
Lagiacrus roar underwater has the same effect as a Sonic bomb on monster.
The Lagiacrus is the biggest Leviathan that dwells in the water, since the Ceadeus is considered an Elder Dragon.
When Lagiacrus hits an underwater pillar or a rock and destroys it, it may drop a 'Shiny' (Offline mode only).
The Lagiacrus is one of the only two monsters in Monster Hunter Tri to have a weapon in every category. The other is Alatreon.
When encountered for the first time offline, in the 1* Village Quest: "Guts- It's what's for dinner"; Lagiacrus cannot be killed. Its body parts can be broken, and its tail can be carved, but it will only go as far as limping, and cannot be killed until the Urgent Quest in the Village.
When present in Deserted Island , Lagiacrus will, on rare occasion, leave the water and venture no further inland than Area 5.
Even if the Lagiacrus' tail is cut or its parts broken in the "Trial of the Sea Dragon" urgent quest, it will return in "Fell the Lagiacrus" healed and unwounded.