GROVER 'STREET'-WISE

The guy is so cool, he's blue. Also fuzzy. Ever since he moved into Sesame Street 23 years ago, Grover the Muppet has never flagged in his enthusiasm and wiry energy. ''I do not know I am cool. Monsters do not know what cool is. I think I am cute!'' he says by phone from the playroom of his right-hand friend, Frank Oz (who, when not hand in glove with Muppets, directed this summer's Housesitter). ''I try to help people. I try to speak correctly. And I just try to be a good guy.'' So good a guy that he might not show this picture of himself to his pals. ''They would feel bad that you do not have their picture,'' says Grover with cool wisdom.