| Issue | #41 |
| Published | February 1968 |
| Cover Price | 0.12 |
| Pages | 36 |
| Editing | Stan Lee |
| Notes | Ink credits from Rich Donnelly via the GCD Errors List. The original indexer credited George Tuska. |
| Characters | The X-Men (Beast, Iceman); Grotesk |
| Genre | superhero |
| Pencils | Don Heck |
| Inks | George Tuska |
| Notes | Heck pencils, Tuska inks per Nick Caputo. Rich Donnelly credited Heck with inks and Tuska on pencils. |
| Characters | The X-Men (Angel, Beast, Cyclops, Iceman, Marvel Girl); V: Grotesk (I; Prince Gor-Tok); I: King Krono, Princess Ingar (both D; in fb); GS: Changeling; GA: Zelda; Vera |
| Genre | superhero |
| Script | Roy Thomas |
| Pencils | Don Heck |
| Inks | George Tuska |
| Letters | Sam Rosen |
| Notes | Changeling is disguised as Professor X. |
| Reprinted | in X-Men (Marvel, 1963 series) #89; in Marvel Special (Marvel Italia, 1994 series) #15 |
| Characters | O: Cyclops (continued); V: The Living Diamond (formerly Jack O'Diamonds); Professor X; Cyclops |
| Genre | superhero |
| Script | Roy Thomas |
| Pencils | Werner Roth |
| Inks | John Verpoorten |
| Letters | Sam Rosen |
| Reprinted | in Amazing Adventures (Marvel, 1979 series) #4 (March 1980); in Marvel Special (Marvel Italia, 1994 series) #4 |