Securing Sean Penn for an animated PG-rated video game adaptation sounded absurd on paper. At the time, Penn was best known for devastating dramatic performances in titles like Dead Man Walking, Mystic River, and Milk. He did not do commercial cartoon voice-overs. Yet, the sheer absurdity of the offer captured his interest.
Entertainment outlets like Vulture and Entertainment Tonight broke the news just weeks before the film's theatrical debut in the spring of 2016, releasing behind-the-scenes images that instantly went viral across social media. The photos depicted Penn inside the recording studio, dressed in an unassuming dark track jacket, leaning intently into a studio boom microphone with eyes narrowed in terrifying concentration.
He was not phoning in stock library effects. Penn stood at the microphone sweating through physical exertion, producing sustained, chest-rattling snarls, sudden aggressive throat clears, and rhythmic, low-frequency hums. The directors provided dramatic context for every scene, directing Penn's grunts as if Terence were navigating a serious psychological crisis rather than an animated bird sanctuary.
The sound design team took Penn's natural baritone recordings, layered them, and slightly lowered the EQ to grant Terence the acoustic presence of an idling semi-truck engine. The result made every appearance on screen an exercise in comedic tension.
