Sally Hawkins to voice character in 'Snail and the Whale'

Sept. 20 (UPI) -- The Shape Of Water actress Sally Hawkins and Game of Thrones alum Diana Rigg will lend their voices to characters in the animated adaptation of Julia Donaldson's 2003 children's book, The Snail and the Whale.

The Magic Light Pictures TV special is expected to air on the BBC in December.

The voice cast will also include Gavin & Stacey actor Rob Brydon and Cariad Lloyd from Peep Show.

"It's always so wonderful to work with Magic Light on these animated specials for Christmas," Brydon said in a press release. "The Snail and the Whale is a longstanding favorite in our house. It's an epic journey across the globe, where the tiniest creature and the mightiest mammal experiences the vastness of our planet together."