The 33-year-old actor won an Academy Award for his portrayal of Stephen Hawking in The Theory of Everything this week, and has signed on to the animated project. Redmayne will voice a character named Ryan, who takes over for Thomas after he is transferred.
"I grew up loving to watch Thomas and his pals getting caught up in unexpected and mischievous adventures," he said in a statement. "I jumped at the opportunity to get involved and what fun it was. I have never voiced an animated character before and I had a complete blast."