Big bird is the tallest creature in Sesame Street. He was the first one to be able to see Snuffy. When he tried to show Snuffy to the rest of the Sesame Street Gang, they were unable to see Snuffy. This happened in maybe the earlier episodes of Sesame Street and that is why some of us may not know about the 'Invisible Snuffy' thing.

Cookie Monster is a blue, furry creature that loves cookies. Whatever it is whenever you see cookies, smell cookies or even hear of the word cookies, Cookie Monster shall be there.

Lovable, cuddly old Grover! He's the one monster that is loved by all. His different characters in Sesame Street makes him a funny and jovial creature.