The shuriken is a new weapon in the Predator’s arsenal, first introduced in Alien vs Predator. It returned again in Aliens vs Predator Requiem and most recently, The Predator. It’s a small compact device that is worn on the Predator’s belt. When activated, the blades expand and it can be thrown. It functions in the same way as the Smart Disc in Predator 2 and can slice through anything. In AvP Requiem, it was able to return to the Predator, suggesting it has some sort of tracking ability built in.
Alien vs Predator (2004)
In Alien vs Predator, the only Predator that uses the shuriken is the Scar Predator. The first time he takes a shot at Sebastian, then slices a Facehugger in half and then kills an Alien with them. The shurikens are also used to fight the Queen.
During production, most of the shurikens were made out lightweight resin but some scenes required them to be more durable. For these scenes to reinforce the the weapon, steel plates were cut to shape and inserted into the mold before the resin was cast. As with the
Predator spear, versions of the shuriken were made both with the blades extended and collapsed, and the transformation was handled digitally.
You can see some concept art of the Shuriken below from artists Joe Pepe and Richard Bennett.
Aliens vs Predator Requiem (2007)
The weapon makes a return in AvP Requiem when the Wolf Predator is at the hospital. He kills two aliens and then pins Jesse to the wall with one.
The Predator (2018)
The shuriken appears again in The Predator and the Fugitive Predator used it when he killed the soldiers in the van when he escaped the laboratory. We later see at the end of the film that one of the soldiers attempts to use one of them that was taken from the injured Fugitive against the Upgrade. The soldier throws it but it returns hitting him.