Ignatius "Iggy" Thistlewhite is a character from the book The Year Without a Santa Claus and its animated adaptation by Rankin/Bass. He is a young boy who lives in Southtown with his parents and an unnamed pet dog. In the original poem, he is stated to be six years old and is the only child in the world who is not upset that Santa Claus is not delivering Christmas presents this year, because he knows that Christmas is about giving and not receiving.
In the animated adaptation, Iggy appears to be a few years older than he was in the original poem. Like in the book, he initially shows no remorse about Christmas being canceled, as he has decided that Santa Claus is not real. But when an undercover Santa comes to the boy's house for information, Iggy's mother invites him inside to take care of his cold. Over a conversation with tea and a song reminiscing about the joys of Christmas, Iggy soon comes to believe in Santa Claus and quickly figures out that his new friend is that same jolly old man.
On the advice of his father, Iggy teams up with the elves Jingle Bells and Jangle Bells to plead their case to the mayor. When their attempt is sidetracked, Iggy is taken on an adventure by Mrs. Claus and the elves to the realms of Heat Miser and Snow Miser. After Mother Nature convinces her two sons to compromise, Iggy is brought back to Southtown and is later shown among the kids making presents to give Santa. Later, when Santa is shown parading through Southtown on Christmas Eve, Iggy is seen waving at him. At the very end, Iggy is last seen giving his parents presents and riding the new bike he received from Santa.