This one is a real "what-the-hell?!" toy from Marx toy company. The company that brought you Rock 'em Sock 'em Robots. Released in 1970 Skinny Bones was a creepy construction kit, that allowed children to build a little freaky friend that same size as them. This cute-faced stick thin creature from the bowels of toy hell was part of a whole family of Bones abominations. There was Ginny Bones, the anorexic female counterpart of Skinny. They also had skinny pets. Skinny Bones had a badly neglected nag called Trom Bones (see what they did there?) And Ginny had an emaciated dog called Ham Bones. I assume that the parts of the Bones Family were all interchangeable, so that children could mix and match parts to create even more hideous monsters, to haunt their nightmares. And bring chills to any parent coming in the bedroom, to give their little cherub a kiss goodnight.
What you would do with either Skinny or Ginny bones after you had built them is a mystery. And as far as the tenuous educational value of, "the foot bones is connected to the ankle bone... etc..." Well I can see very little play value in the Bones Family, but years of counselling for owning this life-size plastic skeletal creep-fest was surely on the cards.
Clip from America TV show Thrift Hunters, featuring Skinny Bones.