Love the variety of head shapes you got going here. I really love the Grandma, she looks so sweet.

I like the murderer one

Strict Mother is the best!

you do such wonderful felines :D
do you have any pointers or tutorials on getting the feline face shape down?
I admit i used "The widow" for a visual reference on a sketch to try practicing the shape (i hope you don't mind, and of course if i upload it I'll credit the visual reference ^^;)

My favorites are the Melancholic, the Barbershop Cat and the Grandma. :)
You really have a feeling for emotions and which "basic shape" (e.g. which spezies or cat type) fits to it best. It reminds me of "Blacksad", where the artist perfected this way of character creation.

Btw, have you ever thought of doing a comic? I still remember the agents from "Unbekannte Einheit". I think you have great potential to do a comic with a story far away from autobiographic daily scribbles and history related graphic "translations" for internet or newspapers.