Tommy, along with his sister Tammy, live miserable lives due to their constantly busy father and mother who is never around, and their evil babysitter robot, who usually tortures them with many weapons. Luckily, like their father, they also have Cosmo and Wanda as their fairy godparents to make them happy and grant them wishes.
Tammy is notable more so in her appearance, which draws features from both of Timmy's love interests in the show, Tootie and Trixie. Her glasses are the same unique style that Tootie's are, and her hair style and hair band resembles Trixie's. Her style of clothing is also similar to Tootie, with a pink color scheme. Her nose is rounded and the front her hair is like Timmy's.
Tommy wears pink clothing and a pink Whoopie Hat, similar to what his father once wore as a kid. Other than the color of his hair, which is black, and his nose, which is pointy instead of round like Tootie's, Tommy is almost completely physically identical to the ten year old Timmy. He also has buck teeth, getting them possibly the same way Timmy did.
Not much else is known about them, as they are only seen briefly at the end of Channel Chasers, digging up a time capsule that their father buried twenty years ago. When they learned that they were going to be babysat by Robot Vicky, they tried to cling to their father's legs while pleading him not to leave, but Timmy shook them off and said goodbye to Tommy and his sister, which is when their names were heard.
Luckily, like their father once did, they also have fairy godparents to make them happy and grant them wishes. Their godparents are none other than Cosmo and Wanda.