Tom Atto is a cook in the undersea palace of Zog the Terrible. He's a fat little man clothed in white, including a white apron and cap. His face is round and jolly, his moustache curls up at the ends, and like all of Zog's slaves he has gills at his throat. (The Sea Fairies)
There is a debate as to whether or not the description of Tom Atto might have been changed at some point because there are three illustrations in the book of a character that is not described anywhere in the book. A theory is that the character, who is tall and lean, with a braided pig tail that has a bow at the end of it, and a large nose (who looks a lot like Ichabod Crane), might represent the original Tom Atto, which was later changed to the description in the book, as stated above. This theory supposes that the tall, lean character looked too much like a character drawn by W. W. Denslow for advertisements of a cereal, named Sunny Jim, so Baum was asked to change Tom Atto's description. But the illustrations of the original Tom Atto obviously slipped by the editors and publishers and were included in the book after all.
If anyone has a different theory of who the tall, lean character is in "Sea Fairies" - please edit this page - or, please comment. ( I wanted to make this a "comment" but I couldn't find how to do it.)