BONUS! Washroom Band, Bird, and Hairy Bart (Patreon)

I suspect this band is a specific reference to some artwork or cartoonist, and that I am about to be shamed in the comments for not recognising what it is:

I feel a little more sure that this bird is not a specific reference: 

And the biggest reference of all: this bearded child is actually a reference to "Bart Simpson", one of the characters from popular television show "The Simpsons":

He would get along with Cool Martin from last episode, I am sure.

This post is part of my "Every Simpsons Character Ever" series. For a list of my rules in this project, click here.