The Star Scouter

The Star Scouter is a difficult Pre-Hardmode boss. It can be considered a biome-specific boss for the Floating Islands, although it will not despawn if taken out of the islands.

While The Star Scouter is alive, the vanilla track Boss 5 will play.

Spawn
The Star Scouter does not spawn on its own, and requires the player to summon it with a Star Caller around Floating Island heights.

Behavior
The Star Scouter flies above the player, launching an array of lasers, beams and energy ball attacks that have varying attributes. Additionally, an eye-like core sits in the center of The Star Scouter and serves to telegraph a variety of attacks.

Attacks

 * The Star Scouter releases a large purple laser blast that explodes upon contact with a tile.
 * At 90% life, The Star Scouter's eye-core begins to periodically take on a downward pulsing animation and target a nearby player. After a short delay, The Star Scouter will hover just above the player and shoot a large, high damage, laser beam that releases two waves on either side of the impact zone. While performing this attack, the Star Scouter will take massively increased damage from melee strikes, indicated by a sword symbol hovering above the boss.
 * At 70% life, The Star Scouter's eye-core begins to periodically take on a plasma ball animation and release a player-homing 'Graviton Surge'.
 * At 60% life, The Star Scouter begins to release three super fast beams instead of firing off its normal large purple laser blast.
 * At 50% life, The Star Scouter begins to release slowly falling energy balls that explode upon tile contact, releasing damaging energy in 8 directions.
 * At 20% life, The Star Scouter again fires its large purple laser blast after the three beams.

In Expert Mode
 * Upon reaching 33% life, The Star Scouter's eye-core takes on a 'buffering' animation. During this time, The Star Scouter becomes invulnerable but passive as it summons the Scouter Cores to attack nearby players. Upon defeating the Scouter Cores, The Star Scouter loses its invulnerability and resume its attacks at a quicker pace than before.

Aftermath

 * Once defeated, the Mechanic will start selling Track Players.

Trivia

 * One of the names of the Star Scouter's attacks, "Graviton Surge", is a reference to the character Zarya's ultimate of the same name from the online shooter game.