Had the Pebbles one, because I liked her yellow shirt with black triangles (plus, Bamm Bamm having white hair kind of freaked me out back then. White hair seems a little unnatural for an infant). I don't believe it was 1970 though, because I was only 2 years old then, and who really remembers anything when they were 2.... but it might've been '72. Basically, when you drank from the cup, somehow the beverage got sucked up Pebbles' and Bamm Bamm's straws at the same time, like you were drinking together, which totally makes sense because who really likes to drink alone...