Below are introduction videos of Mouth of Sauron if you do not remember when he appears and also why he actually gets chooped off. Enjoy and have a good laugh.
Introducing Mouth of Sauron.
This is why Mouth of Sauron gets his head chopped off by Aragon by singing Manamanah...
Note: All pictures of Mouth of Sauron are copyrighted by jimho.