How did Ampharos slip your mind? According to bulbapedia, Ampharos give off so much light that it can be seen even from space, and it's tail's tip shines the brightest. I think that is pretty worthy of Tail Glow.
If you pay attention, he mentioned Ampharos on the last page. He then went on to guess what else could get Tail Glow, suggesting Huntail, and I also suggested Lanturn.
Pay more attention next time.