Cookie Monster, Big Bird and Bert & Ernie were featured as Google doodle. I'm guessing tomorrow will be Elmo. This must be a series of Google doodle featuring the Sesame Street gang.
Some facts about Oscar the grouch, he loves trash and the proof to this is the song "I love trash" that he always sings. From Wikipedia,
Oscar is named after Oscar Brand, a musician and one of the early board members of the Children's Television Workshop during Sesame Street's development in the late 1960s.
If you want to know more about Oscar the grouch, you visit his Wikipedia entry here.
Again, Happy 40th Anniversary to Sesame Street