He were Bozo the clown.
Clarabelle was portrayed by the following...From Wikipedia:
Three actors played Clarabell. The first was Bob Keeshan, who later became Captain Kangaroo. Keeshan was succeeded by Robert "Nick" Nicholson,[1] who also played the character of J. Cornelius Cobb on The Howdy Doody Show. Lew Anderson[2] was the third and last person to play Clarabell. Anderson played the character from 1954 until the series' final show on September 24, 1960.