"Everything... I will devour."
Kamen Rider Gaoh (仮面ライダー牙王（ガオウ）, Kamen Raidā Gaō) is a fictional character appearing in Kamen Rider Den-O. The actor who portrays him is Hiroyuki Watanabe (渡辺裕之, Watanabe Hiroyuki), who had previously portrayed Commander Akio Ishimuro in Ultraman Gaia and Taiga Saejima in GARO. Watanabe, at 51, is the oldest individual to portray a Kamen Rider. Kamen Rider Gaoh and Kintaros were the 48th Super Imaginative Chogokin volume.
Gaoh
Gaoh (牙王, Gaō, literally "Fang King") is a thief-king who targets Time Trains and a renegade Kamen Rider who wishes to take over all of space-time by obtaining the legendary GaohLiner to destroy all time as he was fed up with it. He and his Imagin followers took camp at May, 2000 to await his plan to come to fruition, by sending the Molech Imagin to 2007 to set the pieces up.
Gaoh Form
Kamen Rider Gaoh is the only Kamen Rider in Kamen Rider Den-O to only have one form, called Gaoh Form (ガオウフォーム, Gaō Fōmu) and no Imagin partner (similar to Zeronos Altair Form). It is visually based on a crocodile and is similar to Den-O Sword Form. Upon transforming, Gaoh says "Everything, I'll devour it all" (全員、俺が喰ってやる, Zen'in, ore ga kutte yaru).
Equipment
Gaoh Belt
The Gaoh Belt (ガオウベルト, Gaō Beruto) allows for Gaoh to become Kamen Rider Gaoh. It uses a Rider Pass and SetTouch system, just like the Den-O Belt. However, it uses the gold-plated Master Pass (マスターパス, Masutā Pasu) instead. How Gaoh came to obtain the Gaoh belt and the knowledge of its functions is never disclosed, although it could simply have been summoned with the Rider Pass.
GaohStriker
The Machine GaohStriker (マシンガオウストライカー, Mashin GaōSutoraikā) is Gaoh's personal motorcycle that he uses to pilot the GaohLiner.
GaohGasher
The GaohGasher (ガオウガッシャー, GaōGasshā) is Gaoh's only weapon and only has a Sword Mode (ソードモード, Sōdo Mōdo). It is visually similar to Den-O's DenGasher Sword Mode, except it has a gold, serrated blade. He uses the weapon for his Full Charge attack, the Tyrant Crash (タイラントクラッシュ, Tairanto Kurasshu), which is similar to Den-O Sword Form's Extreme Slash attack.
GaohLiner
The GaohLiner (ガオウライナー, Gaōrainā) was built by the king of an ancient civilization. In the time of said civilization, it was referred to by its actual name, God's Train (神の列車, Kami no Ressha), due to having the power to control all of time, able to easily erase Singularity Points. Due to the vastness of its power, the king sealed the GaohLiner away within the time of its creation. Gaoh sought use of the train, tricking Yukimura into unsealing the cave in which the GaohLiner was sealed in. Upon its release, Gaoh wreaks havoc upon the feudal village before heading into 1988, intent on erasing Ryotaro for having interfered. The GaohLiner battles Zeronos Vega Form until Gaoh attempts to escape in it, engaging the DenLiner/ZeroLiner combo in a battle between the time-trains and is destroyed by them, undoing the damage caused by it.
Kiba
GaohLiner Kiba (ガオウライナーキバ（牙）, Gaōrainā Kiba) is the first car. In Battle Mode, it has jaws like a crocodile, which can not only bite through targets but fire a powerful energy beam.
Other cars
GaohLiner Kiba is followed by several other train cars which do not have any offensive capabilities. They are black, like Kiba, and have two rows of bronze ridges running along the tops of the cars similar to a crocodile's scales on its back. Within each car is a barrage of missiles that are shot at an enemy.