Shirakuna is an alien insect appearing in Gfantis vs THING. It is controlled by Empress Zagi.
Shirakuna is a mantis like kaiju that is reddish-brown in color. It has three eyes, one placed in the center of it's head that is used to fire lasers. When doing so, it usually glows a bright purple, similar to it's wings. It's head is circular in shape and it's mouth goes all the way down to it's neck. It's jaws are filled with tons of razor sharp teeth and two crest like scales run down the top of it's head almost forming a crown of sorts.
Shirakuna was presumably genetically engineered by Empress Zagi and used for conquest, as seen by her confidence it would help her take over the Earth.
Gfantis vs THING
Shirakuna was sent down to Japan by Empress Zagi to help conquer Earth. It began to reek havoc and easily defeated the military. During evacuation of the city it attacked, a man transformed into Gfantis and began fighting it. After a short battle Shirakuna unleashed it's ultimate weapon, a beam that renders its opponents unconscious. Shirakuna then dragged Gfantis away, only for the next night to be electrocuted and have Gfantis regain consciousness. Being paralyzed, Gfantis beat Shirakuna to death, and then exploded the monsters body with a bolt of electricity.
Gfantis vs Rayman X
Shirakuna returns, this time as Mechashirakuna to wreak havoc once again.
- Laser Beam - Shirakuna can fire a purple laser beam that does moderate damage and is capable of destroying military built masers.
- Hypno Beam - Shirakuna can fire off a beam that renders opponents unconscious. When hit by it, Gfantis stopped moving completely and then collapsed.
- Energy Wings - Shirakuna's wings are capable of slicing apart a building.
- Claws - Shirakuna's claws are extremely strong and are capable of destroying buildings and high class military weapons.
Shirakuna seems to be weak to electricity, as after being hit by a couple of electric beams for a few seconds, it collapsed.
- Shirakuna is actually a renamed remake of the Marvel Comics Godzilla villain Rhiahn 
- Shirakuna's nickname, "THING", is a possible reference to Mothra's nickname, "the Thing" which was used on the rather misleading American advertisements for the 1964 Mothra vs Godzilla, in which it was called "Godzilla vs The Thing." This is likely another example of the Gfantis series being heavily inspired by the Showa era of Kaiju films.
- The puppet for Shirakuna was reused in Godzilla: Battle Royal as Rhiahn, the kaiju it was originally modeled after.