The Riddler debuted in Detective Comics #140 (October 1948) and became perpetually forgotten in the Batman comic book realm until Frank Gorshin's over-the-top, Emmy-nominated portrayal of The Prince Of Puzzlers, virtually made him a star overnight on the Batman TV series, as he made the most appearances of any Batvillain in its first season: 8.
When Robin is on the building's edge, the announcer mentions Harold Lloyd. Silent comedian, Harold Lloyd's most famous movie was the 1923 Safety Last in which Lloyd clutches the bending clock hands on the side of a building as he dangles from the outside of a skyscraper above moving traffic.