Kon primarily serves as a comedic foil in the series; when not inhabiting Ichigo's body, his normal plushie body is treated with little respect and much disdain. The humorously cruel treatment he is always subjected to provides the comic relief in Bleach. One of the only people who gives him any respect is Chad; however, Chad ignores him most of the time. His plushie body is a knock-off of the main character of the popular TV show Carnivore Kingdom, named "Ponkichi", which happens to be Chad's favorite show. It was a prize from the shooting game in the Karakura Town Festival.
Here's a link to watch Kon's very first appearance: http://www.youtube.com/watch?v=onDOJ0Rk07M