At the beginning of the 2013 documentary "Growing up With Nine Old Men" film maker Ted Thomas pulls this sketch out of a cabinet. He doesn't give an explanation for the image or who the artist might be. Looking back at the drawing now, I am 89.573 % sure that Milt Kahl drew this during production of Bambi. You remember the scene from the film with Thumper's line about hibernating.
Bambi is a caricature of animator Frank Thomas, Thumper is Milt, and Flower is drawn as Marc Davis, who drew most scenes with that character.
Perhaps Frank and Milt had caught Marc taking long naps after lunch.
By the way, the entire documentary has been uploaded in HD on Youtube: