Giant Form is a transformation used by Annin and Hatchiyack. Bio-Broly also takes on a massive form, due to the Culture Fluid, towards the end of the movie Dragon Ball Z: Bio-Broly. The transformation causes the user to grow to enormous proportions, reaching a size of nearly ten times their original size and increasing their power by an unspecified multiple.
Annin takes on a Giant Form when she battles against Goku. Hatchiyack takes on a giant form in one of the ending scenarios of Shin Saiyajin Zetsumetsu Keikaku - Uchū-Hen, however he is defeated when Goku flies inside him and destroys his core with a Kamehameha. Bio-Broly's version is named Culture Fluid Absorption Gigantification, and he takes the state by absorbing Culture Fluid, growing in height and increasing in power. Super Buu takes on a "giant" form while battling Goku inside his own body, though he is not actually a real giant, he is just larger than anyone inside him. Bergamo can achieve a giant form through damage absorption; for each hit he receives he grows in size and power.
Appearances in games
Annin appears in this form in Dragon Ball Z: Attack of the Saiyans.
In Dragon Ball Z: V.R.V.S., in Vegeta's ending he wishes to Shenron to have "the world beneath his feet", Shenron misinterprets the wish, resulting in him being transformed into a giant standing on the Earth.
in Dragon Ball Online, the antagonist Towa displays the ability to transform characters into giants; she first attempts this ability on Cui, but had not perfected it and causes him to shrink slightly instead. She perfects her ability shortly after, and uses it on Dodoria, Zarbon, Recoome, Frog Ginyu, and several other Galactic Frieza Army soldiers. One Time Breaker Frieza Soldier mutates into a larger form after taking a bite out of the cut off part of second form Frieza's tail.