Rankin formed Videocraft International with Bass in the early 1960s. While their first project was The New Adventures of Pinocchio, Rankin/Bass's most iconic contributions to pop culture are doubtlessly the Rudolph and Frosty specials, which aired on CBS in 1964 and 1969, respectively, and were the two highest-rated programs of the night.
In the 1970s, Rankin produced and directed episodes of the animated Jackson 5 series, appropriately called Jackson 5ive.
Rankin and Bass were later responsible for U.S. distribution of the 1980s Thundercats cartoon, the impact of which can be observed by simply yelling "Thundercats!" in a crowded room. (Anyone who responds "Hoooooooooo!" grew up in the '80s.)
In 1982, Rankin and Bass co-directed The Last Unicorn, which utilized the voice-acting talents of Jeff Bridges, Mia Farrow, Angela Lansbury and Alan Arkin. The cult classic's legacy is notable: The film's animation work was done by the studio Topcraft, later hired by Hayao Miyazaki for one of his early films – and, eventually, Topcraft's core members became Studio Ghibli.
Rankin's influence on animation is enormous. Enjoy this clip of him talking about Frosty, and remember the man who engineered many iconic moments for generations of children.