During the closing end of the Second World War, Navajo Flying "Johnny" Cloud and the Losers were sent on an O.S.S. mission codename Operation Four Horsemen to rescue Colonel Richard "Rick" Flagg and his squad that were stranded on the uncharted Dinosaur Island. Upon violently arriving on the island, Cloud and the Losers were beset by a Tyrannosaurus rex. Cloud and the Losers attacked and fend off the T-rex, but only saw the death of their youngest member Gunner MacKay. Cloud and his team later discovered Flag's fortified cave base and rested there for the night. By the next day Cloud and Captain Storm were awoken from bazooka fire and learned that Sarge went out to kill the T-rex to avenge Gunner's death. The two went out to search for Sarge, but encountering hunting pterodactyls which one of them snatched away Captain Storm.
Despaired in seeing his friend taken away in front of him, Cloud returned to the cave and find Rick Flagg. The Colonel then informed him of Gunner's death and that he is the only one to survive on the island. As the mission was still the Loser's active objective, Cloud and Flagg returned to the island's beach and prepared a raft to leave to a ready seaplane. Cloud, however, informed Flag that he intended to stay, along with Pooch, to avenge his comrade's death by killing the same T-rex they encountered before. Though Flagg tried to reason with Cloud, but relented after the soldier pointed his pistol at Flagg. After spending several days on the island in preparing his fight, Cloud found and followed the T-rex. But along the way, Cloud and Pooch stumbled into one of Rick Flag's traps; killing Pooch and wounding Cloud. Although seriously wounded, Cloud confronted and was able to kill the T-rex by sacrificing himself by priming two grenades and falling into the dinosaur's mouth.
Before his death, Cloud wrote an epitaph on the walls of Flag's cave, attributing to the Losers: "Ask my family and they'll tell you I was a Navajo. Ask the Army Air Force and they'll say I was an American. But if you ask my brothers, they'll set you straight. John Cloud was a Loser."
In the mid-1950s, Rick Flagg honored Johnny Cloud's death by naming America's secret space program: Flying Cloud.
- 2 Appearances of Flying Cloud (Earth-21)
- 5 Images featuring Flying Cloud (Earth-21)
- 1 Quotations by or about Flying Cloud (Earth-21)
- Character Gallery: Flying Cloud (Earth-21)