Tom’s half-brother. Sid is a goody-goody who enjoys getting Tom into trouble. He is mean-spirited but, presents a superficial show of model behavior. He is thus the opposite of Tom, who is warmhearted but, behaves badly. He is whiny and also lives with Aunt Polly and Mary. He appears to be around nine years old. He is always on Aunt Polly's "good side" while Tom is on Aunt Polly's "bad side"...