Sentient Human/Humanoid shaped balloons and inflatables are a common fad every nowadays. When you see one, they're first seen in their deflated state (if it's a balloon, they're in a small human stature and will get bigger when inflated, or, if it's an inflatable, they'll fill out their designated body size). They're often being sold at vendors or balloon stores, and all have varying personalities when first inflated. This is an inspiration of the artist "AECV", and their artwork from Deviantart