Xemnu the Titan (Golden Age monster, Hulk/She-Hulk foe)
Xemnu the Living Hulk, the original Hulk [Journey Into Mystery #62] : r/comicbooks
Marvel Daily Art on X: "And the secret opponent is revealed to be Xemnu, the Living Titan, who was to defeat Hulk for some vague reason. I guess because it's an annual?