Irving is a large blue frog that lives live in the Reservoir along with it's twin Micren. As of late, it's gone missing and not even Micren knows where it's gone. The fight starts once the player obtains the Misery's End weapon, which is ideal for defeating it.
The boss fight plays out like this: there are two fans on each side of the arena, which Serenity can use to jump over Irving. Irving will spend most of the fight hopping toward Serenity, though on occasion it'll either fire energy sickles out of it's mouth (your chance to deal damage) or call upon it's smaller brethren into battle.
Energy Blast (Fires energy blasts out it's mouth, can be attacked)
Frog Hop (Moves forward, deals contact damage)
Call Frog (Summons frogs to rain down on the player, can be killed)
- Irving uses the AI of Balfrog, though it fights differently.
- Though unintentional, Shinica refers to it as a "crazy frog", which references The Annoying Thing (aka Crazy Frog) which coincidently is also a blue frog.
- Irving is one of the two bosses that must be defeated in order to obtain the Map System at the Entrance, the other boss being Sycor.