Bloonarius is an event in Bloons Monkey City consisting of a single battle against a boss bloon, Bloonarius the Inflator, as well as additional bloons that spawn throughout the battle. It first debuted on 6/24/15, and another event began on 7/21/15. The event lasts for 7 days and is linked to the Bloon Beacon, as defeating the Bloon Beacon tile is essential for activating the event.