There are many WW2 based sight gags that would have been familiar to postwar cinema audiences.
Bugs Bunny appears on a mosquito fighter as a mascot. WW2 era bombers were similarly adorned with illustrations and names.
The human is a likeness of Warner Brothers animator/director Arthur Davis.
For all the humor, the representation of boot camp and military ops was fairly accurately depicted.
The recruits are shown entering Anopheles Field. Anopheles is the Latin name for the marsh mosquito.