The Grand Thunder Bird

The Grand Thunder Bird is the earliest boss available to the player and has the lowest health, defense and damage of all the bosses. Despite this, the player is advised to obtain basic equipment before attempting to defeat the Grand Thunder Bird.

While The Grand Thunder Bird is alive, its exclusive Music will play.

Spawn
The Grand Thunder Bird does not spawn on its own, and requires the player to summon it with the Grand Flare Gun. Storm Flares are required as ammunition, and will only be consumed on a successful use. It can only be summoned and fought in the Desert biome during the day.

Behavior
The Grand Thunder Bird hovers a few blocks above the player, flying from left to right. It increases its flying speed when its life falls below 45%. From its high angle, it launches a continuous series of attacks at players.

Attacks

 * With a loud screech, the Grand Thunder Bird brings down bolts of energy that fall from the sky. It is worth noting that the Grand Thunder Bird begins the battle with this attack almost immediately after it has been summoned.
 * The Grand Thunder Bird will level itself to its target's vertical position and prepares itself for its charge attack, signaled by it trembling. After a period of charging, The Grand Thunderbird dashes horizontally at great speed in an attempt to ram the player. This attack can be halted with a melee strike while the Grand Thunder Bird is in the process of charging, which will briefly stun it. A sword symbol will appear above the boss when it charges to indicate this window.
 * The Grand Thunder Bird spawns three Hatchlings to attack the player.
 * Once the Grand Thunder Bird loses enough health, it will start shooting projectiles at the player in bursts of three that deal moderate damage. These projectiles look similar to the bolts of energy the Grand Thunder Bird summons from the sky.

In Expert Mode
 * The Grand Thunder Bird drops bolts of lightning that generate tornadoes upon colliding with a block, akin to its old battle behavior. These tornadoes travel horizontally to the left and right of the impact zone and deal moderate damage. The tornadoes travel for two seconds, are not affected by gravity and can pass through blocks. As the Grand Thunder Bird's health gets lower, it increases the frequency it drops these tornado-generating bolts.

Aftermath

 * Defeating the Grand Thunder Bird for the first time will allow the Desert Acolyte to arrive if provided suitable housing.

Tips

 * The Grand Thunder Bird will always start the battle by bringing down bolts of energy raining from the sky, so it is advised that players disperse the area as soon as they fire the Grand Flare Gun.
 * Players should make use of platforms or vertical outcrops in order to avoid the Grand Thunder Bird's charge attacks. Though risky, players can interrupt and cancel the charge with a well-aimed melee strike.
 * Though Hatchlings can be a nuisance in large numbers, keeping a number alive for possible Heart drops upon death can provide players with a source of healing in an emergency.
 * In Expert Mode, the tornado-spawning bolts dropped by the Grand Thunder Bird can collide with platforms, spawning the tornado on it. This can be used to maneuver a bit easier, alternating platforms as you run back and forth.
 * In addition to this, if the platforms are decently low, the bolts will spawn on the platforms above you, making you completely immune to the tornadoes. However, this may leave the boss out of range.
 * Players can hide under solid blocks in order to protect themselves from the energy bolts and Expert Mode tornado projectiles.