 In tradition with the show 's animation style , Kenny is composed of simple geometrical shapes and primary colors . He is not offered the same free range of motion associated with hand @-@ drawn characters ; his character is mostly shown from only one angle , and his movements are animated in an intentionally jerky fashion . Ever since the show 's second episode , " Weight Gain 4000 " ( season one , 1997 ) , Kenny , like all other characters on the show , has been animated with computer software , though he is portrayed to give the impression that the show still utilizes its original technique . 
