Full Moon (FM) Betta

The Full Moon (FM) Betta is a fancy marketing term used to describe a Double Tail Halfmoon Betta. 

You will occasionally see this term used on YouTube and on AquaBid auctions. 

Since a Single Tail Betta with a 180 degree tail spread is referred to as a Halfmoon Betta; you can reason that a Double Tail Betta has two halves (or Half Moons) that make it into a Full Moon Betta.

Whatever you call them, they are still just Double Tail Half Moon Bettas.

Let's hear it for creative marketing....