The Balloon is one of the, if not the, weakest monsters in the series and are found in the fields around Melromarc. There are three know colors of Balloon that can unlock the yellow, orange, and red small shields. These shields increase defense by +2, +2, and +4 respectively. When the remnants are treated they can be used to create a multitude of items including a volleyball-like child's toy. They have been used by Naofumi as a form of offense and a means of persuasion on several occasions. Late in the series the basic variant of this monster is shown to unlock the Red, Orange, and Yellow Balloon Shields as well as the "Balloon Shield 0/5 C" which has the equipment bonus 「Monster Book」 which is like an encyclopedia of absorbed monsters. Balloons usually fly. They multiply by breaking away from a larger being called Balloon Legios that is almost always airborne and can henceforth freely float in the sky. They become completely independent after separating from the Legios. Naofumi has a balloon slave named Ad Balloon. Found in 『Chapter 5, 134, & 151』 of the web novel.