Gomu Gomu no Red Hawk is a powerful technique of Monkey D. Luffy in the series One Piece. The attack, first shown in Episode 565 of the anime, is essentially a Haki-enhanced version of Luffy's ordinary Gomu Gomu no Pistol. The full name for this technique in Japanese is "ゴムゴムの火拳銃（レッドホーク）" (Gomu Gomu no Reddo Hōku), literally meaning "Rubber Rubber Fire Pistol/Fist Gun".
To throw a Red Hawk, Luffy stretches his right arm back, just like he does whenever he is preparing his basic Gomu Gomu no Pistol. What really sets this technique apart, however, is that as Luffy throws the punch, fire breaks out around Luffy's fist. It is this fiery nature of this attack that really seems to confuse and interest many fans since it does not appear to stay true to the usual laws and aspects of Luffy's rubber body.
The Red Hawk is rather impressive in its functionality, even at places where Luffy's Devil Fruit powers should be weakened. More impressively, Luffy had used this right under the water, which left many people wondering since water is said to make a Devil Fruit user weak. This unusual property has people wondering what kind of technique it is.
One of the main features of the Red Hawk is that it includes Haki. Luffy fuels the attack by using Armament Haki, increasing the overall destructive potential of the attack and adding the advantage of damaging Logia-type Devil Fruit users, since regular attacks would do nothing against them. This combination of Haki and fire-based damage makes Red Hawk a mighty addition to Luffy's arsenal of abilities.
Long time, the source and mechanisms of this attack's fire has been debated among fans. Many of them assume a "fire type of Haki" to explain that and similar techniques used later by other characters like Sanji and Zoro. However, the official explanation is closer to the interpretation that the fire is created by friction. Because Luffy's arm stretches and shrinks so fast, it causes huge friction between itself and the air, which burns his rubber arm.
Red Hawk has been one of Luffy's signature moves during the important parts of a fight. Its graphical display, aside from its power, obviously echoes in fan memory as one of its preferred techniques. Within the One Piece Trading Card Game, Red Hawk is represented by the card "Gum-Gum Fire-Fist Pistol Red Hawk," which has the effect to reduce an opponent's power during the turn it's played.
He has also evolved forms of this process. Fans have theorized how a "Red Hawk Gatling" would be neat, melding the flames from Red Hawk and the sped-up punches of Luffy's Gatling. While the technique would be nice in its visual appeal and may be possibly extremely effective, some fans feel that excessive usage of fire-based attacks could diminish the more special areas of Luffy's rubber powers.
The Red Hawk has been incorporated into the video game adaptions of One Piece as a playable move. However, some players reported that the aiming of the technique can be tricky, especially with a change in camera angle during execution. This brings to the fore one of the challenges of translating Luffy's fluid, unpredictable fighting style into an interactive game.
The Red Hawk is a testament to the growth that Luffy has undergone as a warrior. Now, he can combine his powers with the advanced technique of Haki. This goes a long way in showing how Luffy keeps upgrading his skills, refines himself overtime, and learns to keep up with the very formidable foes living in the One Piece world.