The Yankee Rubber Baby was, as the name suggests, an American-made rubber baby doll. Advertisements for it appeared in many newspapers and magazines throughout the 1880s.
The ads claimed the device could simulate the sound of a baby screaming or cooing happily. I'm not sure how it would have done that. Though I'm guessing there must have been some kind of air bladder that you squeezed to make a noise. But the sound certainly doesn't seem to have been as lifelike as the ads suggested. From a review in Punch (Apr 23, 1881)
The Rubber Baby makes a horrid squeaky noise, is easily blown out, and then goes pop, — quite a little Poppet. What an advantage to poor mothers to be able to pop a Baby! Tell this to the School-Board.
Nevertheless, the Yankee Rubber Baby appears to have appealed to pranksters for its potential shock value, as indicated by the story below, which ran in London newspapers in 1887 [via westhampsteadlife.com
The train was just about to start. There were three of us in the carriage – myself and two ladies – when a young man thrust himself in, carrying a baby. He looked very young to be engaged in such a manner. Young men of about 22 years of age (and he looked no older), do not travel about on the underground railway carrying babies: at least, I had never seen any till now. He seemed very awkward with it, and it protested every now and then. The two ladies began talking, and I listened.
'How nice it is for young men to be so domesticated!'
'Yes, indeed. What a little darling it is too – so quiet.'
'A-a-a! ha a! ha a a!' remarked the little darling.
'Shut up,' said the young gentleman, pinching it.
The ladies assumed a threatening aspect.
'Sir', said one of them, 'babies in convulsions are not usually treated in that manner, and unless you desist at once I shall feel it my duty to call the guard.'
'I'll do what I like,' said the young man, and taking the baby by its long robe, began to swing it round and round, so that its head came in contact with the door frame, after each revolution, the shrieking became terrific.
I got up and pushed him away from the door. Before I could put my head out of the window to summon the guard, however, he laid his hand on my arm, and laid the baby on the seat of the carriage.
'Look here, old man', he said. 'You may call the guard if you like, but recollect that this baby is mine, therefore I've a right to do what I like with it. It's mine – I paid for it.'
'You what, sir?' I gasped.
He sat down violently and said, 'Why what?'
Bang! The train stopped. He got out, leaving on the seat a broken Yankee Rubber Baby.