This is a Mattel Somersaulty the Clown pull string doll. I had one just like this when I was a child. I had a hard time understanding what he said. He was supposed to say, "Do you want to see me do a somersault?" However, it always sounded more like "Do you want to see me suck soapy water?" True story.
NOTE: I had used this anecdote as part of a post on the original blog. I decided to delete that post, but this anecdote made me laugh so hard, I decided to use it in a post here since it had to do with a retro toy of the 70s. Hope you enjoy it.