You encounter Lagiacrus for the first time as an invader in a underwater quest, where you can't kill him, like he's litterally invincible.
go watch the video if you don't believe me.
but anyway, let's cover his moveset on land:
shooting an electric *BALL* towards you.
rushing at you.
bodyslamming.
hipcheck.
biting behind him and swinging his tail.
and bititng twice, knocking you back significantly.
somewhere in the fight, lagiacrus will power up the spikes on his back, wich will charge most of his attacks with lightning and increasing his already lightning based attacks.
and to stop the lighning, you have to break the spikes, but because of lagia being pretty big, you can only hit them with a bowgun or underwater.
since he is a Leviathan, he can go in and out of water at will, wich will change up the fight A LOT.
but most of his underwater attacks are just better land attacks.
and he can now (when supercharged), create a field of lightning around himself.
the rushing attack is now right at you, its just more coordinated.
the electric *BALL* is now more accurate.
and the tail swipe is a bit more rare to see.
he was absent in p3rd, due to no underwater combat in this game, so the dev team didnt add him.
then 3 ultimate came around, Lagiacrus returnign with it.
now he can just hipcheck twice.
when he returned for GU, he also got the on land, thunder field, since no more underwater combat.
and thunder *BALLS* wich will rotate around him.
and some sort of ivory blast.
introduced in 3u, this G-Rank sub-species is a more white colour, and fights mostly on land.
he can use his shell shockers to use the electric field on land.
he can also fire a big thunder *BALL* that will cause some lightning strikes.
The abbysal Lagiacrus is only fought underwater in the underwater ruins, the final boss arena from tri.
he has black lightning, and his shell shockers are always on, so massive thunder damage incoming.
his thunder field is even bigger than that of ivory.
he can also create some whirlpools, wich will last for a few minutes.
and he has stamina drain when he hits you.
he got bassicly all of ivory's changes, even the big thunder *BALL*.