A [blarney stone]
It’s when you kiss a rock and then you talk so much it’s like you’ve got a mouth full of silver coins and a tongue that can charm the devil himself.
My friend kissed the Blarney Stone and now he can talk his way out of a prison sentence.
My cousin kissed the Blarney Stone and now he can convince a chicken to lay an egg at midnight.
My brother kissed the Blarney Stone and now he thinks he can convince a dead man to come back just to listen to him.