The Mysterious Youth (フリーザはボクが倒す... 悟空を待つ謎の少年, Furiza wa Boku ga Taosu... Goku wo Matsu Nazo no Syonen) is the second episode of the Trunks Saga and the one hundred nineteenth overall episode in the uncut Dragon Ball Z series. The episode first aired on December 4, 1991. Its original American air date was September 5, 2000.
As Frieza and his father, King Cold, approach the Earth, the Z Fighters meet up near the landing site and prepare for battle. Without Goku though, they do not believe that they will stand a chance, but Vegeta and Piccolo insist that they must still face Frieza and King Cold no matter what.
Suddenly, Frieza is plagued with his memory of events recently past: he attempted to kill Goku from behind, but Goku counterattacked and apparently destroyed Frieza. Following this, planet Namek exploded, and among the floating rubble and debris, Frieza was still alive, but only barely, and severely damaged and mutilated, as well as only being able to think of how it was "just a monkey" that left him in this state. As his remains floated through space, he was finally found by King Cold, who had gotten wind of Frieza's struggle against Goku and was on his way to aid him.
Frieza was brought on board, taken to King Cold's planet where he's placed in a Medical Machine, and eventually put back together with several cybernetic parts which restored him to full health and brought his maximum power level even higher. Immediately after waking up, Frieza demanded that they go to Earth to blow it up as his first step in revenge on Goku.
Coming back to reality, Frieza orders his men to search Earth for Goku's friends, kill them all and bring the bodies to him. However, a mysterious youth suddenly appears and swiftly cuts the soldiers down. Despite being a stranger, the boy appears to know Frieza, and seems intent on defending Earth from him.
- Despite the title of the episode, Future Trunks doesn't make his first appearance until the last 30 seconds of the episode.
- Frieza's rant during the flashback to his near-death before his failed attempt at backstabbing Goku is slightly different from the episode it occurred in. In this episode, when describing how Goku's puny mind never understood that Frieza is the most powerful being of the universe, he says "And you are nothing more than a monkey!" Originally, he yelled during this instance "And you are nothing more than a beast! A fragile animal!"
- The edited-for-TV version removes the scene of Frieza gripping his fist so hard blood spurts out, and the body parts of Frieza's men falling to the ground after Trunks cuts them up.
- The scene where Frieza is rebuilt is a spoof of "The Six Million Dollar Man", especially in the scientist's monologue in the dub. This is one of the few times the Dragon Ball franchise references a real-world pop culture phenomenon.