 " Walnuts & Rain " first aired on March 5 , 2015 on Cartoon Network . The episode was viewed by 1 @.@ 68 million viewers and scored a 0 @.@ 24 Nielsen rating in the 18- to 49 @-@ year @-@ old demographic . Nielsen ratings are audience measurement systems that determine the audience size and composition of television programming in the United States , which means that the episode was seen by 0 @.@ 24 percent of all households aged 18 to 49 years old were watching television at the time of the episode 's airing . 
