A mighty super-hero hailing from the Earth of a parallel dimension, referred to by some historians as Earth-T (for "Earth-Thunder") and by others as Earth-F (for "Earth-Fauxcett"), whose secret identity is that of young Willie Fawcett, an employee of WHAM-TV. Captain Thunder should not be confused with Captain Marvel of Earth-S, whom he strongly resembles.
Powers: When Willie rubs the magical buckle on his belt and speaks the word "Thunder", he is transformed by a brilliant starburst and a loud thunderclap into the adult Captain Thunder. The Captain possesses super-strength, super-speed, invulnerability to physical harm and the ability to fly, the levels of which make him a peer to Superman in sheer might. In addition, the belt buckle's magical energies give Captain Thunder great wisdom, bravery and tenacity. By rubbing the belt buckle, speaking his magic word and willing it to do so, Captain Thunder can use its power to break the time barrier and travel between dimensions.
Biography: One night, while on a summer camping trip with a group of fellow orphans, Willie Fawcett notices a mysterious owl flying overhead, which seems to beckon the youth to follow it. Pursuing the owl towards the solid rock wall of a hillside, the rock face suddenly opens into a cavern. Willie follows the owl inside and, to his astonishment, encounters Merokee, the last of the Mohegan tribe's great medicine men. Merokee explains that a tribal legend told of a boy of noble spirit who would come forth and be granted great powers by the last of the Mohegan shamans, and that Willie is the boy described in the legend. Holding up a belt with a lightning bolt emblazoned on its buckle, Merokee tells Willie that, upon rubbing the buckle and speaking the word "Thunder", the boy will be invested with seven magical powers as follows: Tornado (power), Hare (speed), Uncas (bravery), Nature (wisdom), Diamond (toughness), Eagle (flight) and Ram (tenacity). Willie rubs the buckle and speaks the magic word as instructed, and is instantly transformed by a brilliant starburst and a clap of thunder into the powerful hero called Captain Thunder. Proclaiming to the Great Spirit that his work is done and that he is ready to pass on, Merokee is transformed into a spirit and soars skyward, leaving Captain Thunder to do battle with the forces of evil whenever and wherever they arise.
Throughout the 1950s on the Earth of his home universe, Captain Thunder battles all manner of crimes and injustices across the globe, becoming that world's foremost hero. His greatest battles are against a coalition of incredible creatures known as the Monster League of Evil, whom he fights across 1,953 different dimensions and finally imprisons in a misty purgatory-like realm. As Captain Thunder is leaving to return to his native dimension, the Monster Leaguers place a curse on the Captain that causes him to turn evil when next he assumes his heroic guise. Through some unknown mishap, Captain Thunder (in his Willie Fawcett identity) winds up in an alley of Metropolis on Earth-1 in June 1974. Given the fact that Willie believes Metropolis to be his home city on his native world, it can be inferred that Captain Thunder is based in a parallel version of Metropolis (albeit in the past). When Willie witnesses an armored car being robbed, he transforms himself into Captain Thunder with the intent of capturing the criminals, but turns to evil as a result of the Monster League's spell. Instead of apprehending the crooks as Willie intended, the Captain begins aiding them in the robbery, which brings him into conflict with Superman. The two powerful heroes engage in a brief skirmish, but Captain Thunder manages to elude the Man of Steel by changing back to Willie Fawcett, who has no memory of what has taken place.
Willie goes to the Galaxy Communications building to find Superman (whom he has seen just prior to transforming into Captain Thunder) in the hope that the Action Ace can help him out of his weird predicament. Willie is directed to Clark Kent (Superman's alter-ego), to whom Willie tells of the circumstances that have lead to him appearing in Metropolis. When Willie, Clark and Lois Lane go to Metropolis Police Headquarters to ask if a Willie Fawcett has been reported missing, the three witness the same crooks involved in the armored car heist trying to break their leader out of jail using a strange aircraft. As Clark slips away to switch to Superman, Willie also ducks out of sight to change to Captain Thunder, who is again seized by the compulsion to perform acts of evil. Instead of aiding Superman in stopping the criminals, the Captain attacks the Man of Tomorrow and the two become embroiled in a titanic struggle that is carried over into the mountains outside the city. At the battle's conclusion, Superman tricks Captain Thunder into changing back to his mortal form, once again regaining his senses in the process. Realizing that he is in the wrong dimension, Willie transforms himself back into Captain Thunder and, while Superman holds the Captain in a full-nelson, forces himself to use his wisdom to break the curse that the Monster League have placed on him. Bidding farewell to Superman, Captain Thunder then uses the power of his magic word to return to his native universe (S No. 276: "Make Way for Captain Thunder").