Gohan new form
You're referring to Gohan's new form in the Dragon Ball Z series!
In the Buu Saga, Gohan transforms into a powerful new form known as Ultimate Gohan (, Sūpā Gohan). This form is achieved when Gohan's potential is unlocked by the power of the Spirit Bomb, a technique used by Goku to defeat Kid Buu.
Ultimate Gohan is a significant upgrade from Gohan's previous forms, granting him immense strength, speed, and durability. His power level is estimated to be over 100 million, making him one of the strongest characters in the series.
In this form, Gohan's appearance changes significantly, with his hair growing longer and his eyes turning a bright blue. He also gains a more muscular build and a fierce determination in his eyes.
Ultimate Gohan is a fan favorite among Dragon Ball Z enthusiasts, and his debut in the series is often cited as one of the most epic moments in the show's history.