CREATE TABLE table_23370 ("N\\u00ba" FLOAT, "Ep" FLOAT, "Huckleberry Hound" TEXT, "Pixie and Dixie" TEXT, "Yogi Bear" TEXT, "Air date" TEXT, "Credited animators" TEXT)

What is the Yogi Bear that aired on 1959.12.21?
SELECT "Yogi Bear" FROM table_23370 WHERE "Air date" = '1959.12.21'
SELECT "Yogi Bear" FROM "table_23370" WHERE "Air date" = '1959.12.21'