Darkrai is a black, shadow-like creature. It has a small head with a white fog-like ghostly substance billowing from its head covering one of its bright blue eyes, and also has a red spiky growth around its neck. It has skinny arms and long black tatters hanging from its shoulders, similar to the tail of Raichu. It also has black, claw-like hands. It has the slight appearance of an hourglass figure and appears to be wearing an old, ripped cloak. It normally doesn't have any sort of legs, but it is able to extend stilt-like appendages in their place. In self-defense, Darkrai also appears capable of retracting its head and white "plume" into the pit atop its torso fringed by the aforementioned red growth.
After Light gets separated from the heroes, he meets with a lost Darkrai in the Reverse World. Darkrai thinks he is responsible for him being there and fights him. In the middle of the brawl, Danny Phantom is wandering the Reverse World lost, and spots the two. He asks them who they are. Light introduces himself and Darkrai fires at Danny. So Danny goes on Light's side and fights Darkrai. Eventually, Danny and Light KO'd Darkrai. But suddenly, Giratina appears and after seing the Knocked Out Darkrai, attacks Light and Danny. Eventually, Darkrai regains conciousness, a Portal appears and Shalos come out to attack 'em. Light, Danny, Giratina and Darkrai join forces to advance to the Portal and escape. After getting out of the Reverse World and finding the Heroes, Danny, Giratina and Darkrai join the heroes.