Member of a group who is considered a disappointment when compared with the superior achievements of Other group Members.
Calling a person Pickle is Personifying the Mc Donalds Pickle, that when found in a burger is considered a let down when compared to ther other contents of the burger.
An alternative for the expression "Ugly Duckling"
Kylie and Dannie Mingoe's brother is the family pickle
That Nick sure is a Pickle, his family are all so good looking and really smart- I don't know what went wrong with him.