Comic Title: Challengers of the Unknown #20
Publisher: DC (National Comics Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: Jun/Jul 1961
On Sale Date: April 13, 1961 Copyright Date April 13, 1961
Source: Library of Congress, Periodicals 1961

Frequency: Bi-monthly
Cover Price: $0.10
Page Count: 32
Editor: Jack Schiff

Title: "The Cosmic-Powered Creature"
Pages: 12

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

Artist: Bob Brown

Reprinted In:
Showcase Presents:Challengers of the Unknown Vol. 2 TPB (2008)

Feature Character(s)

• Challengers of the Unknown (last appearance in Challengers of the Unknown #20; next appearance in Challengers of the Unknown #21)
• Ace Morgan (last appearance in Challengers of the Unknown #20; next appearance in Challengers of the Unknown #21)
• Rocky Davis (last appearance in Challengers of the Unknown #20; next appearance in Challengers of the Unknown #21)
• Red Ryan (last appearance in Challengers of the Unknown #20; next appearance in Challengers of the Unknown #21)
• Prof. Haley (last appearance in Challengers of the Unknown #20; next appearance in Challengers of the Unknown #21)

Supporting Character(s)

• June Robbins (last appearance in Challengers of the Unknown #20; next appearance in Challengers of the Unknown #21)

Villain(s)

• A flying lion, a walking whale, and a giant baboon (victims of cosmic rays; no further appearances)

Other Character(s)

• Captian Carlson (an astronaut; no further appearances)

Synopsis:
An astronaut’s space capsule lands on the west coast of Africa. The Challengers travel to the scene to rescue the downed pilot. They discover the capsule, but the pilot has wandered off.Rocky and Ace scout the area from the air and are attacked by a flying lion. Meanwhile, June, Red, and Prof chase off a giant baboon which is threatening a nearby village. After overcoming the two threats both groups locate the pilot.

Ace and Rocky approach him and at the same time a walking whale attacks. Rocky suddenly grows to giant size, while Ace begins to glow and gains super powers. The two men fight off the beast, and Prof explains that the pilot is giving off cosmic radiation which is causing the transformations. He comes up with a method of removing the radiation from the pilot, which also somehow restores the transformed men and beasts to return to normal.