Alfred Pennyworth (somethimes know as Beagle) may have been created
at the instigation of the producers of the first Batman movie serial.(Written
by Victor McLeod, Leslie Swabacker, and Harry Fraser). Or maybe not.
In any case, comic sidekicks were all the rage in 1943 when Alfred made
his first appearance in Batman 16.
from "Here Comes Alfred" by Don Cameron, Bob Kane and
Jerry Robinson Batman 16 4/43
The serial came out in July 1943 and featured the tall skinny William
Austin in the role of Alfred. It took awhile for the comic books
to adjust to the new look.
from "Accidentally on Purpose" Detective Comics 83 by
Don Cameron, Bob Kane and Jerry Robinson, January 1944