| Unofficial Challengers of the Unknown Index |
Credits:
| Art | Bob Brown |
| Lettering | Stan Starkman |
| Associate editing | Murray Boltinoff, George Kashdan |
| Editing | Jack Schiff |
Feature Character(s):
Villain(s):
- Immortal Man (Torbert; first appearance; an assistant to an archaeologist who steals a formula that temporarily conveys immortality)
Other Character(s):
- Pharaoh Tut Aba (first appearance; an immortal Pharaoh; also in flashbacks)
Location(s):
- Egypt
Story Reprinted in:
- Showcase Presents Challengers of the Unknown #2 (2008)
Credits:
| Art | Bob Brown |
| Lettering | Stan Starkman |
| Associate editing | Murray Boltinoff, George Kashdan |
| Editing | Jack Schiff |
Feature Character(s):
- Challengers of the Unknown:
- June Robbins (next in issue #25/2)
Supporting Character(s):
Villain(s):
- Kugaby (first appearance; a humanoid alien that creates a large robot to help him get a rare mineral to power more robots)
Location(s):
Story Reprinted in:
- Showcase Presents Challengers of the Unknown #2 (2008)