Liquefied Form (Etrian Odyssey IV)Edit
This monster is encountered on the B2F and B3F of the Hall of Darkness, and is never encountered alone. Like the Magma/Glacier spawn this guy won't attack you, though if you happen to off any of it's allies it will change. For this reason, this is one of the priority targets to eliminate unless the party has a method to shut it down.
Solid Form (Etrian Odyssey IV)Edit
|Resistance||All Physical, Volt|
It is strongly recommended that you eliminate the Thunder Spawn(s) before any other enemy on the field because if you don't, the Thunder Spawn will shift into its solid form and spam extremely powerful electric attacks to your entire party indefinitely. Not only that, its HP will dramatically increase. Because it is considered a separate entity, the solid Thunder spawn, on transformation, will lose all buffs, debuffs, binds, and ailments.
One tactic to fight this monster is to Quick Step one of your Medics so that he/she can constantly heal the party from the Unloads. With two characters occupied, you can use the other three characters to throw in as much fire and ice attacks as possible. Since its Unload skill uses its head, landing a head bind on it will also prevent it from doing a thing to your party for a long time, letting you quickly eliminate it or the other threats.