Otto the Grouch

 Otto the Grouch  is  OSCAR THE GROUCH  's baby brother. He ' s also the baby brother of Ernest the Grouch  &  Oscar  ' s sister  Bunny, making him the 3 rd son of  Mr .  &  Mrs . Grouch. Otto is both seen & mentioned in the 1976 book   How to Be a Grouch .

Books

 *  How to Be a  GROUCH  ( 1976 )