1.The kid in school who would remind the teacher about the homework.
2.The slow witted 18 year old girl who goes 35 in the left lane.
3. Chet from Wierd Science, Dr. Chilton from Silence of the Lambs, or Carrot Top.
4.The sibling/cousin/assface that snitches to your parents when you're smoking pot in your room.
Also see "No talent ass clown".