The glow fish is a citizen of Rock Bottom who is a good friend of SpongeBob. Unlike the other Rock Bottomites, he is capable of speaking without a Rock Bottom accent. He is named for the glowing lure on top of his head, which illuminates the area around him.
He is dark pink and has a lure on his head with a red orb on the top, which glows. He wears a purple bow tie that wraps around his neck. He has three dark red spots on both sides of his head, a pink dorsal fin, red eyes, and dark purple lips with a normal pink tongue. He looks much more normal in comparison with the other Rock Bottomites.
His color palette is different in a well-lit environment, as seen in "The Night Patty." His irises and tongue are purple, his spots are yellow, and his light and fins have a yellow outline.
After getting off the bus, he was asked by SpongeBob for help but seemingly ignores him by chasing after his glove balloon. He later finds SpongeBob and returns the balloon to him, after which he inflates SpongeBob's balloon to float back to Bikini Bottom. SpongeBob is happy to the thought of going home and says "Thank you!" in the tongue accent, but the glow fish responds by saying "You're welcome!" in a normal accent, much to the surprise of SpongeBob who joyfully goes home while the glow fish waves.
He is one of the few Rock Bottomites that appear when Squidward is delivering food to 237 Rock Bottom. When Squidward is scared of the Rock Bottomites, calls the Rock Bottomites monsters, SpongeBob appears to correct him, by saying that they're his friends. The glow fish then asks SpongeBob "what's up," before he and the other Rock Bottomites put on party hats and blow raspberries.