Much like its weaker sibling, the Elder Lavos Spawn should be defeated by hitting the head with your best single-target damage. Attacks against the shell will incur a counterattack–but unlike its younger sibling, this counterattack will only hit a single party member (the one who hit it first).

Elder Lavos Spawn can still use its Needle Spin to damage the entire party, as well as use Water- and Shadow-based techs to do heavy damage to one of your party members. Defeat it like you would the other, but be more conscious of the damage you take from this one, as it is far more dangerous offensively.