Notes
New creature in Summer Update 2008 After Summer Update's first patch (8.21), it's debatable if Sea Serpents keep dropping their old rares.
Abilities
Melee (0-200), Earth Wave (60-300), Ice Wave (101-300), Drowning Bomb 20 hp/6 turns, Fast Self-Healing (around 250 hp/turn).
Damage Taken From Elements
Location
Strategy
For all vocations: Their wave attacks cover more area than other monsters wave attacks so is harder avoid, still standing diagonally is your best option, even walking slowly.
You can remove the helmet of the deep and put again to cancel the drowning bomb, this will save you around 100 hp.
Also: You need to go up and down alot to hunt them so levitate spell is a must or bring Ice Cubes or Pots (monsters don't push them) and you can use them to use Ledgehopping to minimise the damage that you can take.
Mages: With level 90 and higher use Energy/Death/Earth Strike combined with an underworld rod. With lvl 60+ you can easy kill them with mana shield and sudden death runes. Explosion runes are also good.
Paladins: You need good skills to solo them (around 80/70 skills), they are weak to melee so Ethereal Spear can do more damage than Divine Missile. Lower level paladins should have a blocker.
Knights: Lure single Sea Serpents and fight them with Exori and Exori Gran. Heal early with Strong Health Potions or better.
Loot
0-234 gp, Bag, 0-4 Meat, 0-3 Dragon Ham, Viking Helmet, Plate Legs, Sword, 0-3 Small Sapphire (semi-rare), Spirit Cloak (semi-rare?), Glacier Amulet (rare), Ring of Healing (rare), Strong Mana Potion (semi-rare), Serpent Sword(semi-rare), Focus Cape (rare), Northwind Rod(rare), Strong Health Potion(semi-rare), Glacier Kilt(rare), Stealth Ring(rare), Great Mana Potion(rare), Leviathan's Amulet (rare?), Thaian Sword?? (very rare), Crystalline Armor (very rare?).