Here are the sketches I made while creating this cartoon.
The cartoon began with a request from a reader, Caroline V., for a cat cartoon for her birthday. After I read that email, I got the idea and quickly scribbled down the sketch at the top left. Then I refined the chicken section of the cartoon with the other sketches on the left, moving the speech balloon and changing the chicken expressions.
And then, since I don't draw Aliens very often, I worked through that part of the drawing several times, refining it slightly each time. You can see how the aliens change slightly from sketch to sketch. Here's the final cartoon.