Frieza's Final Transformation! The Ultimate Nightmare Begins! (フリーザ最後の超変身！地獄以上の恐怖がはじまる,Furīza Saigo no Chō-Henshin! Jigoku-ijō no Kyōfu ga Hajimaru, lit. Frieza's Final Transformation! The Ultimate Nightmare Begins!) is the fortieth episode of Dragon Ball Z Kai. The episode first aired in Japan on January 17, 2010. Its original American air date was October 28, 2010. Its Dragon Ball Z counterparts are "Another Transformation?" and "Dende's Demise". The song "Only a Chilling Elegy" is played in this episode.
Frieza manages to dodge Gohan's attack, but is quickly found on the receiving end once again. Gohan fires an attack that even the tyrant himself has difficulty deflecting. To show Krillin, Gohan, Piccolo, Dende, and Vegeta a "terror beyond death", Frieza begins his transformation into his fourth form. Vegeta's plan is to get Krillin to blast him so that Dende will heal him, and he will finally become a Super Saiyan. However, after Krillin blasts him, Dende refuses to heal him after what he did to the Namekians, and Vegeta falls unconscious. Dende heals Piccolo, who in turns tells Dende to heal Vegeta, stating that Vegeta is better than Frieza. Frieza then completes his transformation, and kills Dende, seeing first hand while Dende healed Vegeta. Krillin, Gohan, and Piccolo try to attack Frieza while Vegeta watches from atop a hill, but Frieza is too fast. The show ends with Gohan directly in the path of one of Frieza's Death Beam.
After Krillin says how scrawny Frieza looks after his transformation, Piccolo calling Krillin an idiot has been removed.
As Frieza aims his finger beam at Dende, his line was changed from "Bang" to "Bye-bye".