[4] Flash Gordon and his son Rick escape from Ming the Merciless, who has exhausted the natural resources of his home planet Mongo and desires to exploit Earth.

Ming tries to brainwash Flash's wife Dale Arden, but she resists until death, whereafter her psyche is later included in the Defenders' supercomputer Dynac X.

[5] To protect Earth from Ming's invasion, among other threats, Flash joins forces with Mandrake, his assistant Lothar and The Phantom, alongside their children, to form the Defenders.

A line of action figures produced by Galoob included Flash Gordon, Mandrake, Lothar, the Phantom, Ming, and Garax.

[19] As part of the show's 35th anniversary, National Entertainment Collectibles Association (NECA) produced variants of its King Features characters in the style and colors of the Defenders of the Earth.

A video game was released by Enigma Variations Software in 1990, for the Amiga, Atari ST, Commodore 64, Amstrad CPC, SAM Coupe and ZX Spectrum systems.

It is a side-scrolling action game featuring the heroes Flash Gordon, Lothar, the Phantom and Mandrake from the series on a quest to rescue their children, who have been kidnapped by Ming.