Hanson's first appearance was in Dewey's Special Class, where he was one of the emotionally disturbed students, placed in a specialized classroom. When Dewey got sent there, he had to make a new circle of friends, which included Hanson. Hanson proved to be a schizophrenic, who believed that he was riding a motorcycle at all times. When the teacher asked him to read a passage from a book, instead of reading the words, he just made an extremely loud screeching sound.
In Hal Sleepwalks, the school president election was happening and a bully nominated Hanson as a joke. Hanson knew that he did this so that he could watch him humiliate himself and ultimately fail, but he thought he'd get revenge on him by actually becoming a good candidate and getting elected, unironically. Unfortunately, upon trying, Hanson had a mental break down, during his speech and started cursing rampantly, revealing that he has tourette's syndrome.
- David mainly goes by his last name, "Hanson" as opposed to his first name.
- It's possible that he's the younger brother of Eric Hanson, given that they both have the same last name and similar physical appearances. Due to Eric going absent from the series in season 3 and David not debuting until season 5, they have never interacted, so we may never know.
- It is implied in a few episodes that he has a crush on Zoe Desenea.