Western Bucking Bronco
US toy companies Ajax, Beton, and Lido during the 1950s and 1960s made a type of hard plastic bucking bronco horse seen here. They are usually but not always marked inside the body with the company name.
The easiest way to tell them apart at a glace is the difference between saddle pommel and the rope coils.
See also the Western Running Horse for another type made at the same time by these companies