Character Clues
Character Analysis
Occupation
If you were reading this tale around the time it was written, you might have been immediately suspicious when you read "Pardoner." You would have known that Pardoners were notorious for ripping people off by selling fake relics and pardons. Pardoners were allowed to keep a certain percentage of what they took in, but unscrupulous pardoners were a huge problem for the Church in medieval times. So you would have probably settled into the story with certain expectations.
Direct Characterization
The Pardoner is very upfront in describing himself as a fraud and a huckster. He explains that he has to "wynne," or earn money, in order to buy all of the food, clothes, and prostitutes that make possible his luxurious lifestyle. We don't have to infer anything about his character. He does the same for the characters in his tale, describing them as rioters, guys who live to drink, curse, and carouse.
Actions
In both the Pardoner's Tale and Prologue, we learn a lot about about characters by what they do. But it gets more specific than that, because in the morally charged setting of the Pardoner's confession and "moral tale," all we really know about what characters do is how they sin. We watch the rioters getting drunker by the second, cursing and carrying on at the bar and rushing impulsively out on a crazy mission to kill "Death." Obviously, they're not the brightest bulbs in the pack. Like the Pardoner, they're greedy; they see the eight bushels of gold they find as money to feed their sinful appetites for gambling, drink, and women. They make fun of an old, sick man. And they're totally without a conscience; they'll kill their buddies just to keep more of the gold for themselves.
It's not surprising that the sinful characters in the Pardoner's Prologue and Tale all look pretty much the same: part of the point of the Tale is how one sin leads to another – how sin creates a "chink" in your moral armor that allows the devil to take over your soul. The characters may have initially become sinners through one or another particular vice, but they all end up looking like each other, concerned about nothing except what benefits them.
We learn something about our Host in his violent reaction to the Pardoner at the end of the tale. He's not just the genial, jolly innkeeper. When the Pardoner singles him out as someone particularly in need of buying some repentance and pretty much invites him to "kiss my relics," the Host picks up on the dig and tells him he'd rather cut off his "relics" and enshrine them in pig turds. Ever gallant, the Knight steps in before anything gets out of hand.