The Reporter notes:
... [Oscar nominee Chris] Miller will reprise his role as Kowalski the penguin in DWA’s Madagascar 3: Europe’s Most Wanted, which opens June 8.
The director also lent his voice to his feature Puss in Boots, playing the roles of Little Boy Blue and one of the guards. ...
Several weeks ago when I inverviewed Mr. Miller, I intended to ask him about his voice work. But during the course of our conversation, it slipped my mind. (Drat!)
I don't know how long the tradition is for feature animation directors to give voice to animated characters, but back in the 1970s, Disney veteran (and feature writer) Larry Clemmons voiced Gramps the swamp turtle in The Rescuers.
(Larry was also a talented voice director. He was adept at getting performances out of seven and eight-year-old actors on The Fox and the Hound. Watching him coach and coax the kids into solid performances on the recording stage was a thing of beauty.)