The best friend ribbon is a ribbon that appears in the episode "Wormy."
It is a small, orange and light blue ribbon. The words "best friend" is written on it in red text inside of a white explosion bubble.
Role in episode
SpongeBob makes the best friend ribbon for Wormy after he and Patrick play with him for the entire day. However, once Wormy transforms into a butterfly, the best friend ribbon comes off of him.
The next day, SpongeBob and Patrick look inside of Wormy's jar onto finding a "monster" with the best friend ribbon on the bottom of the jar, thinking the "monster" ate Wormy.