Rocket J. Squirrel is the cartoon flying squirrel protagonist of the 1959-1964 animated television series The Rocky and Bullwinkle Show, produced by Jay Ward. Rocky is the brains of the “moose and squirrel” duo, though he often appears just as naïve and gullible as Bullwinkle. When he flies, he is accompanied by a jet engine sound effect.
P.S. “And now, here’s something we hope you’ll really like!”