Comic is an index of Marvel characters employing text, original art, and previously published clip art; Joe Rubinstein is listed as inker and James Fry as art enhancer, so both are listed as inkers for all entries; All entries for Eliot Brown are for equipment diagrams; All series volumes are from Silver Age on
- Cloak to Doctor Octopus - Wraparound Cover
- Scientific Method - Page contains artist credits, table of contents, indicia, plus an article explaining the criteria for inclusion in the index
- Cloak - 1st Appearance Spectacular Spider-Man (Marvel, 1976 series) #64
- Cloud - 1st Appearance Defenders (Marvel, 1972 series) #123
- Cobra - 1st Appearance Journey Into Mystery (Marvel, 1952 series) #98
- Collector - 1st Appearance Avengers (Marvel, 1963 series) #28
- Colossus - Brother of Magik; 1st Appearance Giant Size X-Men (Marvel, 1975 series) #1
- Constrictor - 1st Appearance Incredible Hulk (Marvel, 1968 series) #212
- Contemplator - 1st Appearance Marvel Treasury Special Featuring Captain America's Bicentennial Battles (Marvel, 1968 series) #1
- Controller - 1st Appearance Iron Man (Marvel, 1968 series) #12
- Corruptor - 1st Appearance Nova (Marvel, 1976 series) #4
- Corsair - Father of Cyclops and Havok; 1st Appearance X-Men (Marvel, 1963 series) #107
- Cottonmouth - 1st Appearance Captain America (Marvel, 1968 series) #310
- Crimson Dynamo - 1st Appearance (as Crimson Dynamo) Iron Man (Marvel, 1968 series) #109
- Crossfire - 1st Appearance Marvel Two-In-One (Marvel, 1974 series) #52
- Crusader - 1st Appearance Thor (Marvel, 1966 series) #330
- Crystal - 1st Appearance Fantastic Four (Marvel, 1961 series) #45
- Cybele - 1st Appearance Eternals (Marvel, 1985 series) #1
- Cyclops - Son of Corsair; Brother of Havok; Husband of Jean Grey; Father of Cable and Phoenix [Rachel Summers]; 1st Appearance X-Men (Marvel, 1963 series) #1
- Cypher - 1st Appearance New Mutants (Marvel, 1983 series) #13
- Dagger - 1st Appearance Spectacular Spider-Man (Marvel, 1976 series) #64
- Daily Bugle - 1st Appearance Amazing Spider-Man (Marvel, 1963 series) #1
- Daredevil - 1st Appearance Daredevil (Marvel, 1964 series) #1
- Darkstar - 1st Appearance Champions (Marvel, 1975 series) #7
- Dazzler - 1st Appearance X-Men (Marvel, 1963 series) #130
- Death - 1st Appearance Captain Marvel (Marvel, 1968 series) #27
- Deathbird - Shi'ar; 1st Appearance Ms. Marvel (Marvel, 1977 series) #9
- Deathlok - 1st Appearance Astonishing Tales (Marvel, 1970 series) #25
- Death-Throws - 1st Appearance Captain America (Marvel, 1968 series) #317
- Deathurge - 1st Appearance Marvel Two-In-One (Marvel, 1974 series) #71
- Destiny - 1st Appearance X-Men (Marvel, 1963 series) #141
- Deviants - 1st Appearance Eternals (Marvel, 1976 series) #1
- Diablo - 1st Appearance Fantastic Four (Marvel, 1961 series) #30
- Diamondback - 1st Appearance Captain America (Marvel, 1968 series) #310
- Doc Samson - 1st Appearance Incredible Hulk (Marvel, 1968 series) #141
- Doctor Demonicus - 1st Appearance Godzilla (Marvel, 1977 series) #4
- Doctor Doom - 1st Appearance Fantastic Four (Marvel, 1961 series) #5
- Doctor Druid - 1st Appearance Weird Wonder Tales (Marvel, 1973 series) #19
- Doctor Octopus - 1st Appearance Amazing Spider-Man (Marvel, 1963 series) #3
- Glossary - The inside back cover contains a glossary that is continued from last issue and a text article, "Scientific Method", continued from inside front cover.
Glossary contains the following entries: magic; mass accruing; metamorph; microverse; micro-world; multiverse; mutagenic; mutant; mutate; mutation; Negative Zone; nexus; omnipotent; omnium; pantheon; parallel Earth; parallel world; phase; pocket-dimension; polymorph; precognition; prosthesis; psi; psion; psionic; psychic; psychokinesis; Pym particles; radar sense; robot; sentient; sorcerer supreme; soul; space warp