The show's title characters are a pair of alien brothers named Guapo and Fraz, both of whom work as couriers, who travel throughout their universe to deliver packages to a different planet in each episode of the series.

In the series, they work for a company called RetroGrade Interdimensional Couriers, of which a green-colored female alien named Tarara Boomdeyay is the boss.

[12] Laura Sullivan, the senior director of marketing of Sony Wonder, said in a 1999 Promo article that the series attracted equal numbers of male and female children and that it was "very Nickelodeon-looking.

Fast food chain KFC announced that it would use the characters in a kids' meal, while Carl's Jr. and Hardee's branded tray liners and bags with The Brothers Flub images.

[11] GNC planned to include The Brothers Flub yo-yos in its children's vitamins, while department store chain Macy's used the characters in their back-to-school advertising flyers.

"[18] The Hollywood Reporter called it "a somewhat vacuous effort that lacks the charm and substance of much of Nick's other programming" but added "now and again [the creators] hit on some clever high jinks.