Tenebrous is a fictional character appearing as an enemy of a character created by who ?
Tenebrous (Marvel Comics): Tenebrous is a fictional character, a Marvel Comics cosmic entity appearing as an enemy of Galactus. Galactus:  Galactus was created by Stan Lee and Jack Kirby and first appeared in the comic book "Fantastic Four" #48, published in March 1966.
Stan Lee and Jack Kirby