According to sources such as the Sesame Workshop website and Sesame Street Unpaved, the character's name is spelled "Snuffleupagus".
Sesame Street Unpaved is a name used for numerous Sesame Street related productions.
Sesame Street | Coronation Street | The Wall Street Journal | Wall Street | Shortland Street | Hill Street Blues | Oxford Street | 10 Downing Street | Homicide: Life on the Street | E Street Band | Fleet Street | High Street | Manic Street Preachers | Wall Street Crash of 1929 | Regent Street | Downing Street | Sesame Workshop | Street Fighter | King Street | High Street, Oxford | Russell Street | Sauchiehall Street | Russell Street, Melbourne | Great Ormond Street Hospital | Flinders Street | Broad Street | Yonge Street | Liverpool Street station | Flinders Street Station | A Nightmare on Elm Street |