| Issue | #29 |
| Published | February 1967 |
| Cover Price | 0.12 |
| Pages | 36 |
| Editing | Stan Lee |
| Notes | Disputed penciler credit--Werner Roth alone per Steve Whitaker, Nick Caputo, Carl Gafford, and Michael Evans; Werner Roth with Jack Kirby per the original indexer. |
| Characters | The X-Men (Beast, Iceman, Cyclops, Marvel Girl, Angel); Mimic; Super-Adaptoid |
| Genre | superhero |
| Pencils | Werner Roth |
| Inks | John Tartaglione |
| Notes | Disputed penciler credit--Werner Roth alone per Steve Whitaker, Nick Caputo, Carl Gafford, and Michael Evans; Werner Roth with Jack Kirby per the original indexer. |
| Characters | The X-Men (Professor X; Beast; Iceman; Cyclops; Marvel Girl; Angel); Mimic; Super-Adaptoid (Villain); Factor Three (Villain) |
| Genre | superhero |
| Script | Roy Thomas |
| Pencils | Werner Roth |
| Inks | John Tartaglione |
| Letters | Sam Rosen (pages 1-3, 10-20); Artie Simek (uncredited, pages 4-9) |
| Notes | Mimic leaves X-Men, next app. in INCREDIBLE HULK #161. Lettering credits provided by Rodrigo Baeza. |
| Reprinted | in X-Men (Marvel, 1963 series) #77; in Marvel Special (Marvel Italia, 1994 series) #12 |