Derek Generic is Bobby's 10-year-old brother, with a rat-tail hairdo and a sarcastic manner. He absolutely loves horror movies and skateboarding. He always calls Bobby names, such as "Dork," "Pea-brain", and "Dweeb," (voiced by Kevin Smets seasons 1-5 ,Pamela Segall season 6-7 and Zachary Gordons in Bobby's World 2.)
Bobby keeps listening to Derek's lies and cruel jokes.
Derek was supposed to be his swimming buddy; however, he ditches Bobby so he can go to the pool.
As mentioned in "The Revenger of Dr. Noo", he was kicked out of the Scout Rangers.
Also reveals that Derek gets bullied by his peers so he takes his anger and frustrations out on Bobby to feel better.