The first step in solving this puzzle is identifying all the cartoon characters. Once they have been identified, the numbers can be used to index into the characters’ names to give two letters per character.
LEONARDO (Teenage Mutant Ninja Turtles) – L, O
JUNIOR ASPARAGUS (VeggieTales) – N, G
SUZY SHEEP (Peppa Pig) – E, S
KATARA (Avatar: The Last Airbender) – T, R
BARNEY RUBBLE (The Flintstones) – U, N
SONIC (Sonic Boom) – N, I
BUGS BUNNY (Looney Tunes) – N, G
WANDA (The Fairly OddParents) – A, N
KIMI (Rugrats) – I, M
SPONGEBOB SQUAREPANTS (SpongeBob SquarePants) – A, T
WENDY (Gravity Falls) – E, D
BULLWINKLE (The Adventures of Rocky and Bullwinkle and Friends) – K, I
SCROOGE MCDUCK (Teenage Mutant Ninja Turtles) – D, S
PHINEAS (Phineas and Ferb) – S, H
WINNIE THE POOH (Winnie the Pooh) – O, W
The given letters spell out the phrase LONGEST-RUNNING ANIMATED KIDS SHOW, which gives ARTHUR, which just ended earlier this year after a twenty-five year run on PBS.