Yucky Pierre is a Grouch seen once on Sesame Street in Episode 1056. A loose parody of Julia Child, also known as "The French Chef", Yucky Pierre (or "The Grouch Chef"), is played by Oscar the Grouch.
Oscar (as "Yucky Pierre" with a French accent), demonstrates how to make Charles's Chicken Soup. He and his assistant Charles add various, disgusting ingredients to the pot, none of which are chicken. The chef asks Charles to taste it, but he backs away. Oscar reveals why the soup is named such, because Charles is too chicken to eat it!