Deb Turnbull is the wife of Dwight Turnbull and mother of Tommy and Donnie Turnbull. She serves as a common housewife. Deb is a very kind and sweet woman to her family, and is always looking out for them. Her head is similar to Tommy's, having a square head, but with red hair. She is voiced by Lorraine Pilkington. In the live-action films, she is portrayed by Amy Adams.
It's clear that Tommy gets most of his facial appearance from his mother, except for the red hair, including the square head and big circular eyes. The rest of her appearance consists of a midriff tank top, Capri pants, and boots in the first season, and then just heels in the second. Her most notable feature, however, is her noticeably fat bottom. So much that in most of her appearances, her bottom is viewed on screen.
Along with shared appearances, Tommy and her have (almost) identical personality traits in that they're both the only two in the family with good hearts and normal intelligence. Although, despite the fact she makes it clear that she loves him and the rest of the family with all her heart, she's more strict and stern when he steps out of line, even through misunderstandings. And despite being of normal intelligence, she still sometimes can make rather oblivious mistakes herself due to her rather naive nature.
- Of all the episodes in the series, Deb appears in 46 episodes.
- Like all mothers, she tends to punish Tommy if he is seen to have done something terribly wrong. Examples include Cleaning Day, when Tommy fails to clean his room when she tells him to, or, in I Want That Toy, when Tommy gets framed for stealing a toy, which was actually Robotboy in his backpack, and when he sneaks out to prove his innocence.
- In her character profile in the Robotboy - Special Edition CD-ROM, it is said that Deb works as a librarian in charge of the town's bookmobile.