Blappy is an old Blobule (72 years old to be exact) that is purple in color.
During the events of Chapter 4-2, Blappy can be found in his house at the very end of Planet Blobule. He is known as the elder of Planet Blobule and mentions that he was searching for a certain treasure in space. However, his direct role is to sell the Ancient Clue to the heroes for 1,000 coins. However, this is an amount that the heroes cannot possibly hold and must refuse this offer where Blappy can drop it to 100 coins. They can also decline his offer and Blappy will drop the price to 10 coins. The heroes must accept this offer or Blappy will bring the price back up to 100 coins and will not drop the price again.