Comic Title: Challengers of the Unknown #47
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: Dec/Jan 1965
On Sale Date: October 7, 1965 Copyright Date October 7, 1965
Source: Library of Congress, Periodicals 1965

Frequency: Bi-monthly
Cover Price: $0.12
Page Count: 32
Editor: Murray Boltinoff

Title: "The Sinister Sponge"
Pages: 11

Feature(s):
Challengers of the Unknown (of Earth-1)

Writer: Bill Finger
Artist: Bob Brown

Feature Character(s)

• Challengers of the Unknown (last appearance in Challengers of the Unknown #46; next appearance in Challengers of the Unknown #48)
• Ace Morgan (last appearance in Challengers of the Unknown #46; next appearance in Challengers of the Unknown #48)
• Rocky Davis (last appearance in Challengers of the Unknown #46; next appearance in Challengers of the Unknown #48)
• Red Ryan (last appearance in Challengers of the Unknown #46; next appearance in Challengers of the Unknown #48)
• Prof. Haley (last appearance in Challengers of the Unknown #46; next appearance in Challengers of the Unknown #48)

Villain(s)

• Stacy (a small-time crook; no further appearances)

Other Character(s)

• The Sponge (aka Miklos; next appearance in Challengers of the Unknown #51)
• Lisa (Miklos's neighbor; next appearance in Challengers of the Unknown #51)

Synopsis:
While diving, a man named Miklos cuts himself on a meteor rock with a sponge growing from it. The meteor transforms Miklos into a sponge creature. He contacts the Challengers for help. While the Challs attempt to find a cure, Miklos's neighbor Stacy tricks the man by claiming an expensive doctor can help. Miklos uses his amazing sponge powers to help Stacy commit crimes. The Challs finally convince Miklos that Stacy is using him. Without a cure, Miklos runs away and hides on the ocean floor.