Two years ago I made two hats from the book Brei De Leukste Dierenmutsen van Vanessa Mooncie & Rebecca Mothersole (http://www.ouderwetsbreien.nl/boeken/brei-de-leukste-dierenmutsen/).
It was fun making them and with a large hook it was finished off quickly.
Our rabbit Lizzy was model for the rabbithat.
I’m happy with it (right one).
The ears were done with doubleyarn. Unfortunately it became too heavy.
Did you ever make an animal hat for adults?