Disambiguation: Pinky the Whiz Kid / Mr. Scarlet
First published in: 1941
Pinky first appeared in Wow Comics (Fawcett, 1940 series) #4 (Winter 1941-1942); he donned a costume and was adopted by Brian Butler (Mr. Scarlet) in that same issue. Pinky became the second Mr. Scarlet in The Power of SHAZAM! (DC, 1995 series) #44 (December 1998). His first name, Phineas, was revealed in Stargirl: The Lost Children (DC, 2023 series) #6 (July 2023).
Link: https://en.wikipedia.org/wiki/Mr._Scarlet_and_Pinky_the_Whiz_Kid