Dr. Lowell Herder is a pediatrician who appears in the fourth season Dinosaurs episode "Terrible Twos." The Sinclairs seek the doctor's help when Baby Sinclair turns two. Earl requests a sedative, but while the physician can dispense dangerous drugs at will, he chooses not to in this instance. Following the examination, Dr. Herder instead recommends setting concrete bounadries, specifically by walling the child inside a cave for a year.