Mopee. The name might resemble a feeble structure and tickle your funny bone (though funny bone is not a bone), he is the real reason behind the Powers of Barry Allen (The Flash), Bruce Wayne (Batman), Superman, Peter Parker (Spiderman), Dr. Bruce Banner (The Hulk), Fantastic Four and The Avengers.
First mentioned in The Flash Vol. 1 #167 named 'The Real Origin of the Flash', Mopee explained how he was the one behind flash's powers.
Once while Barry is fighting some Gang of Smugglers, his protective aura vanishes, bursting him into flames. Mopee, the reveals himself introducing himself as Initiate Tenth Class Of The Heavenly Help-Mates. He explains Barry that his Super-Speed powers are no accident, in fact, are the gift of super-speed that is bestowed on Barry by Mopee on orders of his superior. Mopee then tells him to give away his powers as their is error in the selection of Human for this super-speed as the chemicals which contributed in the Police-Medical Laboratory at the time of Lighting-Strike didn't belong to Barry. But in order to keep the Super-Speed, Barry has to earn the Chemicals as The Flash not Barry. Allen then publishes an ad in the news-papers as shown in the above picture and earns the chemicals. Mopee then returns the aura to Barry and leaves the planet.
After this, Mopee reveals himself as the cause of creation of several Marvel and DC Superheroes. As mentioned in Comics, Mopee reveals that he was the one gifting powers to the Superheroes. The proof image is :
However, Mopee, even after being short and feeble guy, managed to prove that he was Heavenly Powerful.
For Reference, Watch : https://www.youtube.com/watch?v=bRZK0cRgqi8