Friend is an average-sized jellyfish with a blue-colored body and seven navy-blue/dark-blue spots.
Personality and habits
He is the stealthiest and fastest of every known jellyfish SpongeBob had caught, not to mention being the smartest jellyfish of them all due to his evasion maneuvers.
Like all jellyfish, Friend can create an electric shock/sting that causes the body parts of a hostile person to swell up. However, it is also shown that Friend can hold back his sting if, for any reason, he wishes not to harm someone, as seen when he taps SpongeBob on the shoulder while inside the factory.
Friend also has the ability of stealth, speed, and intelligence. It is also shown that Friend is skilled at using a jellyfish net and a jar, and somehow knows SpongeBob's phone number, therefore making him the smartest jellyfish.
He is initially called "No Name," until the end of the episode, when SpongeBob names him "Friend."
Role in episode
He avoids being caught by SpongeBob. After being sent by Mr. Krabs to catch every jellyfish for their jelly and the population of Jellyfish Fields is depleted, SpongeBob is followed by No Name when going back to his house. He is captured by the blue jellyfish when he cuts the electrical wire and lures SpongeBob with a Krabby Patty made from his own jelly.
Fortunately, No Name doesn't wish revenge on SpongeBob. He instead brings SpongeBob to a factory and shows him the inside where every jellyfish SpongeBob caught is being brutally tortured and their jelly is being extracted. SpongeBob then sees Mr. Krabs in the factory and realizes he is the one who deceived him into catching the jellyfish just for money.
No Name and SpongeBob storm into the factory, stop Mr. Krabs, and free the remaining captured jellyfish who proceeded to sting Mr. Krabs in revenge. As thanks for rescuing his kindred, No Name allows SpongeBob to catch him, and No Name is renamed to "Friend."
In the Morris Broadband description of the episode, No Name is called Ol' Buzzy.
When SpongeBob tries to catch him, the caption reads "Bring it on!"