Fantastic Four (1961 1st Series) #235...Published Oct 1981 by Marvel

"Four Against Ego!" Part 2 of 2. Script and art by John Byrne. Cover by John Byrne and Terry Austin. The Fantastic Four are locked in a life-and-death struggle against the Living Planet, Ego! How can the FF defeat an entire planet? When Reed, Sue, and Johnny fall before the internal heat and pressure of the powerful bio-verse that is Ego, only the Thing remains to save the world! Can Ben find the living brain of Ego and destroy it? Cameo appearance by Frankie Raye. Note: Flashback cameos by Thor and Galactus to recap Ego's previous appearances in Thor 227 and 228.