Herbert "Herb" Jacob is Junie B.'s best friend in first grade. They sit next to each other on the bus on the way to and from school. He seems to dislike May as much as Junie B. does. In Junie B. Top Secret Personal Beeswax, he and Junie B. seem to have a crush on each other.
Herb is shown to be helpful and a good friend. As seen in "Cheater Pants" he heard Junie B struggling and gave her his anwser on the test. He also gave Junie B half his sugar cookie in "Boss of Lunch" so that's how caring he is.