Abbott and Costello were an American comedy duo composed of comedians Bud Abbott and Lou Costello, whose work in radio, film, and television made them the most popular comedy team of the 1940s and 1950s, and the highest-paid entertainers in the world during the Second World War. Their patter routine "Who's on First?" is considered one of the greatest comedy routines of all time, a version of which appears in their 1945 film The Naughty Nineties. Abbott and Costello made their film debut in the 1940 comedy One Night in the Tropics. The following year, they appeared in three war-themed comedies: Buck Privates, In the Navy, and Keep 'Em Flying. They also appeared in the 1941 horror comedy film Hold That Ghost, and went on to appear in several other horror comedies, including Abbott and Costello Meet Frankenstein (1948), Abbott and Costello Meet the Killer, Boris Karloff (1949), Abbott and Costello Meet the Invisible Man (1951), and Abbott and Costello Meet the Mummy (1955). Other films starring the duo include Pardon My Sarong, Who Done It? (both 1942), The Time of Their Lives (1946), Buck Privates Come Home (1947), Africa Screams (1949), and Abbott and Costello Go to Mars (1953).