You can see in Megazor's camp that Galladians, Zorodotd, and Roscopores are many of the alien creatures they've faced in previous episodes.
The screenplay for this episode is loosely based on Richard Connell's 1924 short story "The Most Dangerous Game," in which a big game hunter who lost interest in stalking animals hunts humans instead. It was updated for the show to imply that the "true purpose" of the hunt was to determine whether Megazor was fit to be a ruler.
Per the title, The Hunter's Moon is the first full moon after the harvest moon, which is the full moon nearest the autumnal equinox.
You can see that alien monster Galladian is wearing the same helmet that Judy the Chimpanzee wore when she played Penny Robinson's alien pet Debbie the Bloop.
The title does not refer to any of Earth's Moon phases, but to the fact that the episode is about a hunter.