Great-Grandfather Turtle is a minor character from Franklin's Magic Christmas. He was Franklin and Harriet's maternal great-grandfather, as he was Mrs. Turtle's maternal grandfather, which in turn was due to being her mother Jenny's father. He is only shown in a flashback episode taking place when Grandma Jenny was a child.
In the story, Jenny went out to the woods with him, but wandered off. Offscreen, Jenny's father has been looking for her. When he does find her (unaware that she is hiding a magic bell in her muff), he asks if she didn't hear him calling.
He was voiced by Richard Newman, the voice of his then-future grandson-in-law.