Thomas' Animal Ark is the first Christmas episode of Thomas and Friends: Big World! Big Adventures! it debuted on Channel 5 on December 10, 2018 and Nick Jr. on December 15 the same year.
When the boiler at the Animal Park on Sodor breaks down on a cold, snowy day, Thomas decides to take the animals to the Steamworks where they will be warm. However, snowdrifts on the line make the journey impossible, so he takes them instead to Tidmouth Sheds - where the engines are forced to spend the night with elephants, giraffes and an ostrich!