Harold Joseph Wallis is a retired American center fielder who spent five seasons in Major League Baseball with the Chicago Cubs and Oakland Athletics. He was nicknamed Tarzan because of his penchant for cliff diving. A native of East St. Louis, Illinois, Wallis attended McCluer High School and Southern Illinois University Carbondale. In 1971 and 1972, he played collegiate summer baseball with the Chatham A's of the Cape Cod Baseball League. He was selected by the Cubs in the sixth round of the 1973 MLB Draft.