"The Doll You Dress In a Snap". Made in 1979 by Knickerbocker but heavily marketed in the 80s, Dolly Pops were simple, small plastic dolls just an inch or two high.
They had no poseable limbs and their clothing came as complete outfits (with accessories like bikes or sometimes pets!) that 'snapped' or rather 'popped' on in one piece. Sort of like a 3D plastic version of Paper Dolls, but they had synthetic ponytails even though their scalps were plastic, which was quite bizarre, which you could brush and style.
There were also special Dolly Pops carry cases available, like you get with Polly Pocket dolls. When you opened them up an entire scene was revealed which you could use during your play with Dolly Pops. They had various themes, like sports, market, western theme, shopping etc.