Order:Leviathan - Suborder:Sea Wyvern- Infraorder:Thunder Shell Wyvern- Family:Lagiacrus. The Lagiacrus is one of the most famous and feared Leviathan, a group that also includes Agnaktor, Uroktor, Royal Ludroth, Gobul , Nibelsnarf, and Kuarusepusu. Lagiacrus also has two different variants, Ivory Lagiacrus, Lagiacrus that have been feeding on quartz, and Abyssal Lagiacrus, old individuals found deep in the abyss.
Lagiacrus are found in the Deserted Island and Flooded Forest. Despite its ability to come up on land, they prefer to stay by deep waters. They rarely need to travel far from water, due to the abundance of prey in both of their tropical environments. Being such powerful swimmers it is very possible that Lagiacrus and its two Subspecies can travel far distances and be seen in other habitats.
Lagiacrus is the top predator of its habitat, and even predators such as Rathalos and Rathian prefer to keep out of its way. Of course being the Lagiacrus' only real competition, the Fire Wyverns would be considered a threat to a Lagiacrus, as would a Lagiacrus to a Fire Wyvern. Despite this, these monsters tend to stay out of each other's way at all costs, especially if the encounter is between a pregnant female of either species that is about to lay her eggs. However, a battle between a Rathalos and a male Lagiacrus is considered to be one of the most spectacular (and dangerous) things to ever witness. Lagiacrus's control of Thunder Element (an element which most underwater monsters are weak against) makes it a dangerous adversary in the aquatic habitat it resides, even for the well defended Gobul of Flooded Forest. Even Plesioth that migrate to the Deserted Island and Flooded Forest would be wary of the large and powerful leviathan as its powerful electrical attacks can easily cripple or even kill the Piscine Wyvern. This causes Plesioth to avoid Lagiacrus and its two Subspecies at all costs.
Lagiacrus is a large, blue aquatic leviathan, adapted to life in tropical waters. Its hood-like structure is similar to that of a Chameleos. It also looks like a cobra. The large dorsal spikes on its back are used to release its electric attacks alongside a possible electro sac below each spike. The spikes glow white in rage mode or very pale red when out of the water long enough. Also, when performing its thunder attack, it will cease to move around and look like it is shriveled up and will be glowing bright aqua blue. It is unknown if charging up if it hurts the leviathan, as it always gives a scream when releasing energy, but it's most likely using up stamina. When it is low on stamina it will fail to charge.
Best known to live in the sea, as it is well adapted for living in it. With its white-ish underside mimicking the reflection of light on water surface and its blue top which blends in with the water around it, the Lagiacrus can hunt prey from both below or above without being seen.
While Lagiacrus is very well adapted to the sea, it is also found in the murky river beds and steamy, wet jungles of the Flooded Forest. Here its main prey of Epioth, Aptonoth, Slagtoth, and Ludroth are still hunted and new food items like Arowana and Catfish are also added to the menu. Lagiacrus remains the top predator, and is able to remain so due to its sheer power and unique ability. Lagiacrus, as an air breather, lives a perfect life in both fresh and salt water.
Unlike most other monsters (but like most other leviathans) the tail of a Lagiacrus is not designed to be a weapon in any sense, but rather to be a tool to help propel the beast through the water. Although they tend to travel at a cruising pace, one lash of their flattened tails is capable of sending them forwards at a frightening speed, easily fast enough so that it can leap clear out of the water, either onto land or into the air, where it might be able to catch hold of a careless flying creature. This is not to say though that they are not capable of going on the offensive with their tails though. Indeed, they might use it in a similar manner to how crocodiles sometimes use their tails, which sometimes give struggling prey a whack with it to stun or even kill it. Given that a Lagiacrus' tail is very long, heavily muscled towards the base, flexible, & slender towards the end, they might be able to either give large prey or tormentors like a Rathalos a hammer blow with the trunk or a smack across the face with it, or, for smaller things, use it to send something tripping up or to stun them with a flick of it like a bullwhip.
The scales of this powerful leviathan are large, thick, interlocking, & yet quite flexible, giving this monster a terrific form of natural body armor. The real ace in the hole to this though, it the fact that the Lagiacrus has a very low ground clearance. This is good because it makes the Sea Wyvern tricky to flip over, but it doubles because, being low to the ground, other creatures will be forced to attack it from above, where its scutes, scales, spikes, & horny plates will protect it very well from attack, whilst, being relatively flat, will enable Lagiacrus to attack its assailants, who will find their body armour redundant, as it will be on the top of their body whilst the Lord of the Seas attacks their (relatively) soft underbellys.
The Lagiacrus' teeth are shaped much like that of a crocodile: large and thick, capable of inflicting puncture wounds which allow its powerful jaws to hold onto land dwelling monsters and the unfortunate hunter with the intention of dragging its prey into a watery grave. It has a very long body, which makes it more agile underwater than other Leviathans, and it can easily adjust its underwater trajectory.
Lagiacrus appears to have a slow metabolism, as it rarely seems to become hungry when fighting hunters. This allows Lagiacrus to somewhat coexist peacefully with their two even more powerful subspecies. However, conflicts between the three species do occassionly happen.
Lagiacrus mainly prey on large Fish, Sharq, Epioth, and on occasion Ludroth, although they may sometimes attack land-based herbivores. They may wait by the shoreline for anything coming by for a drink then ambush its target, using their highly specialized tail to propel its bulk out of the water, clamping its jaws on the surprised victim, and pulling it into the water, much like a crocodile. Lagiacrus will sometimes come up onto the land itself and stalk the jungle or valley in search of any unsuspecting prey. Whether on land or in water they are formidable fighters. They appear to be aggressive, but not territorial. It is unknown what would happen if it were to meet the rare Ceadeus. It is also known to retreat to the water and eat an ever unfortunate Epioth to regain stamina when fatigued. When charging electricity, the water will boil as it does so. This is the Lagiacrus actually splitting the water molecules around it. This process is called electrolysis and occurs when a direct current is added to in this case water to create steam. This aggressive Leviathan is known to sunbathe and sleep as far inland as possible, as long as there remains an expansive stream or puddle of water.
They seem to be very aggressive towards humans. They are known to frequently attack boats, making them a feared and dreaded enemy of sailors. This human-aggressive attitude makes it dangerous to sail or even hunt in areas where Lagiacrus have been spotted. There have even been cases where a rookie hunter hunting Epioth for their guts encounters a Lagiacrus up close, leading to an attack. Veteran hunters should be careful of this Leviathan, and even the hunters just starting out must be wary of an encounter with the Lord of the Seas at the most unexpected times.