How to obtain the Bloop Whistle in Fisch

The Bloop Whistle, a new item in Fisch, is crucial for obtaining the Astraeus Serenade fishing rod. It summons a Bloop Fish, a requirement for a new questline. This rare item can be purchased from the Daily Shop with a 0.5% chance or earned as a reward from completing Angler NPC quests, which have a 1.60% chance of yielding the whistle. The Bloop Whistle triggers a 10-minute global event to catch the Bloop Fish, which has a "Line Breaker" ability that players must manage.