Inflatable T. Rex Costume You've seen it go viral, so you know your kid will love it. We're a fan of this Chasing Fireflies Inflatable T. Rex Costume ($69) because not only does it make a giant statement, but it also stays nice and puffy. The included fan requires four AA batteries. Image Source: chasing-fireflies.com Inflatable T. Rex Costume $69 from chasing-fireflies.com Buy Now