A Dr. Strange villain, better known for his playable appearances in the Marvel vs. Capcom series, who is a part of a 'great old ones'-like pantheon. Shuma Gorath was first used in a 'Kull' story titled 'The curse of the golden skull' and written by Robert E. Howard, which went unpublished till 1967. Although he frequently appears as a purplish octopus, there is some debate as to whether this is his true form or simply the form his energy takes while in our dimension.
His major appearances follow.
-Marvel Premier #14, march 1974
-Conan the barbarian, vol 1, #240 and #260
-Marvel Premier #3-10
-Marvel Knights 4, issues #25-27, 2006
-Strange tales vol 2, #13, #14, #15
His official scores are as follows, with 1 being normal human and 7 being godlike.
Energy projection: 7
Fighting skills: 4
Major Enemies: Dr. Strange, The Fantastic four, Sise-Neg, many others over many time periods
Other aliases: Cthuma-Abath, He who sleeps but shall awaken
Sources: Wikipedia, Marvel Universe Wiki, Handbook of the Marvel Universe