Comic Title: Superboy #120
Publisher: DC (National Periodical Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: April 1965
On Sale Date: February 18, 1965 Newsstand Date February 18, 1965
Source: House Ad, Action Comics #322, Page 32

Copyright Date February 18, 1965
Source: Library of Congress, Periodicals 1965

Frequency: Monthly, with the exception of Feb., May, Aug. and Nov.
Cover Price: $0.12
Page Count: 32
Editor: Mort Weisinger

Title: "The Invulnerable Imp"
Pages: 8

Feature(s):
Superboy (of Earth-1)

Writer: Edmond Hamilton
Artist: George Papp

Reprinted In:
Superman Family #170 (1975)

Feature Character(s)

• Superboy (last appearance in Adventure Comics #331; next appearance in Adventure Comics #334)

Supporting Character(s)

• Jonathan Kent (last appearance in Superboy #119; next appearance in Superboy #121)
• Martha Kent (last appearance in Superboy #119; next appearance in Superboy #121)

Villain(s)

• Mr. Mxyzptlk (last appearance in Superboy #114; next appearance in Superboy #131)

Synopsis:
Mxyzptlk has his name legally changed to Mxypyxm before returning to plague Smallville. Since his new name is a palindrome, it is the same backwards as it is forwards. Mxyzptlk therefore can't be tricked into returning to his own dimension. Superboy is helpless, until he devises a plan to use amnesium dust which erases Mxyzptlk's short-term memory. Superboy then tells him that he is trapped on Earth. Just to be sure, Mxyzptlk declares his name is Mxyzptlk again and speaks it backwards. As a result, he is sent back to his own dimension for at least 90 days.