Tiger claw strike
Toraken-uchi (literally: “tiger-fist strike”), the tiger claw strike emulates having a tiger's paw for a hand, allowing you to claw your opponent’s eyes out.
To perform a tiger claw strike, splay your fingers out, bending them at the second and third knuckles, such that they resemble a tiger’s claws, like in the picture below:
[photos of a hand in a tiger claw from the front and the side]
Place the tips of your index and ring fingers on the center of the opponent’s eyebrows, then snap your elbow into your chest, and snap your wrist forward. The end result is somewhere between an effeminate hand gesture and a downward backfist strike, which will rake and pierce the opponent’s eyes with your fingertips. The index and ring fingers do the majority of the damage; the other fingers serve as redundant backups if the opponent turns their head to avoid the strike.
[video of tiger claws from the front and side]
Tiger claw strikes often follow rising palmheel strikes; the tiger claw is a “bonus technique” which is spontaneously included to enhance and augment a waza, just like how grace notes are used in jazz performances. Tiger claw strikes from the side are uncommon, but cromulent.
Tiger claw strikes are forbidden in kumite, because they target the eyes. Tiger claw strikes are typically reserved for advanced students, not because they are difficult, but because up-and-coming karateka should concentrate on more important things.