babble-baby
A babble-baby is someone who talks so much and about such stupid stuff that they might as well be a walking joke.
'I'm a babble-baby. I said the moon is my sister and the clouds are my pets.'
Tweet: 'My neighbor is a babble-baby. He talks about fish, cars, and why Tuesday is the worst day.'
Text: 'I just realized I'm a babble-baby. I talked about pizza, math, and why the grass is green. All of it was nonsense.'