Disambiguation: Superman's pal
First published in: 1938
Jimmy Olsen first appeared, as an unnamed office boy, in Action Comics (DC, 1938 series) #6 (November 1938). He was first named on The Adventures of Superman radio program on April 15, 1940 ("Donelli's Protection Racket"). His first name was mentioned in a comic book for the first time in Superman (DC, 1939 series) #13 (November-December 1941), and his last name was given in issue #15 (March-April 1942). Jimmy was first shown using a signal watch to contact Superman in Superman's Pal, Jimmy Olsen (DC, 1954 series) #1 (September-October 1954). Perry White first said to Jimmy "...and don't call me 'Chief'!" in issue #8 (October 1955). Jimmy first became Elastic Lad in issue #31 (September 1958). He first became Flamebird in Superman (DC, 1939 series) #158 (January 1963). The character was revamped by Jack Kirby in Superman's Pal, Jimmy Olsen (DC, 1954 series) #133 (October 1970). Jimmy began using the nickname "Mr. Action" in issue #155 (January 1973). Jimmy Olsen's history was revised in The Man of Steel (DC, 1986 series) by John Byrne. Jimmy first appeared as a super-hero named Mr. Action in Countdown (DC, 2007 series) #41 (September 2007).
Link: https://en.wikipedia.org/wiki/Jimmy_Olsen