Ya want space opera?
Now here's SPACE OPERA!
...starring the one-and-only Flash Gordon as rendered by EC Comics legend Wally Wood!
Illustrated by Wally Wood and his studio.
Wood (and writer Harvey Kurtzman) had previously-done the hysterical MAD parody "Flesh Garden" (which you can read HERE), but this is his only "official" Flash Gordon work.
The writer is unknown.
Though Flash had his own comic at this time, this three-parter appeared in the back of The Phantom's title from the same publisher, King Comics.
The particular tale appeared in the back of The Phantom #18 (1966), which was actually the first issue of the series from King Comics.
(They just continued the numbering from the previous publisher, Gold Key!)