Abstract: A balloon for interlocking with another balloon that includes a body of an elastically expansible material formed into a substantially closed shape so as to define an expansible chamber therein, inflation apparatus for allowing a pressurized gas to enter and inflate the body, and interlocking apparatus for allowing one balloon to interlock with another balloon. The inflation apparatus includes a pair of tubes of an elastically expansible material and which extend axially and collinearly from, and are integrally formed with, opposing ends of the body and terminate in open ends with circumferential lips, and are in fluid communication with the expansible chamber for allowing the pressurized gas to enter and inflate the expansible chamber. The interlocking apparatus includes the inflation apparatus being tied by a string after the body is inflated, and with the string tying the inflation apparatus of one balloon also tying the inflation apparatus of an adjacent balloon so as to from a chain of balloons.