Crane is a boss from Final Fantasy X. It is a part of the Oblitzerator battle, and though it does not have turns during the battle, is a targetable enemy. The crane only becomes a target once Lulu notices it during the battle. The high HP value is to discourage players who may have "grinded" their characters to a high level to not destroy the crane. Destroying the Crane may have some harmful side effects, such as crashing the game. This is because there is no "death" animation and defeating it could effectively crash the game.
Lulu will point out the crane during the battle. Casting Thunder upon it three times will allow Tidus to use the Trigger Command, Use Crane. This will cause severe damage to the Oblitzerator and prevent it from using its finest attack.