Super Saiyan 4 is a transformation that first appeared in the anime series Dragon Ball GT. It is the fourth level of the Super Saiyan transformation and is considered to be one of the most powerful forms in the whole Dragon Ball universe.
To achieve Super Saiyan 4, a Saiyan must first achieve the Golden Great Ape form, which can only be achieved by a Saiyan with a tail looking at the full moon while possessing enough Saiyan Power. Once a Saiyan achieves this form, they must learn to control it and transform it into their Super Saiyan 4 form.
In this form, a Saiyan’s hair becomes longer, and their body is covered in red fur. Their eyes turn black with a red outline, and they gain a muscular build, making them much stronger and faster than before.
New cosplay emerges to recreate the iconic transformation that only Goku and Vegeta were capable of achieving. Comicbook.com spotted the following post on Instagram:
Goku achieved the Super Saiyan 4 transformation through a combination of intense training and a special method. First, he trained in the Other World for seven years, where he increased his power level significantly. Then, he was required to control his Great Ape form by mastering his emotions and regaining his consciousness while transformed. Finally, with the help of the Old Kai, Goku got his tail grown back, which helped him achieve the transformation.
As for Vegeta, he had to use the Blutz Wave Generator that was created by his wife, Bulma. This device simulated the light of a full moon, which allowed the Saiyan Price to transform into his Great Ape form and then back into a humanoid form with the power of the transformation remaining.
In other words, only Goku achieved the Super Saiyan 4 transformation by truly earning it. Vegeta would have never been able to do it by himself, without the help of his wife.