Dr. David Nelson

Dr. David Nelson is a man with dwarfism who comes to the South Park Elementary to give a talk about his experience in the eleventh season episode "With Apologies to Jesse Jackson". He was voiced by Trey Parker by taking in helium to create the distinct high pitched voice.

Personality
Dr. Nelson seems to be a very learned man having published six books in total, but after being pushed too far in terms of mocking his dwarfism he acts childish with constant attempts to get back using juvenile methods. He does seem to have little concern over his condition if he is not teased by it too much, and constantly claims that he feels "Words are like bullets, and I let them pass straight through me."

According to Kyle, Nelson has a black belt in karate which seems to show he is strong as well, but during his fight with Cartman this does not seem the case.

History
Nelson's only appearance is the episode "With Apologies to Jesse Jackson", in which he first appears to give a talk at South Park Elementary to all students. Upon entering he is laughed at and mocked by Cartman, which Nelson dismisses believing he'll stop eventually. Later he complains to Principal Victoria and Mr. Mackey claiming if he could have one-on-one tuition with Cartman he could change his views, but as Cartman is sent in he begins to laugh again causing Dr. Nelson to have an outburst, yelling "Shut your fucking mouth!" to the shock of Principal Victoria. He is clearly embarrassed by this, claiming it was a joke. Next he gets all the fourth graders to say "Hello fatso!" when Cartman enters the room which they do, and upon questioning who organized this Nelson reveals himself only to cause Cartman to laugh even more. Finally, they have a fight which Cartman gains the upper hand of making Nelson repeat a line said by a short person in the film Poltergeist. Cartman goes off guard for a few seconds only for Nelson to push him to the floor, and he then leaves believing he's proven his point.