super saiyan 4
A form of Super Saiyan that appears in the anime-only Dragon Ball GT. Born from gaining control over the Golden Oozaru form, its main features are red fur covering the torso, longer hair, and red lining around the eyes. Son Goku is the first to achieve this form, followed by Vegeta and their fusion, Gogeta (whose Super Saiyan 4 form is different from his fusees, since his hair turns red and his body gains brown fur instead). It can be upgraded into Super Full Power Saiyan 4.
Dragon Ball Heroes would later introduce a further evolution to this form, with the long name of Super Full Power Saiyan 4 Limit Breaker.
This tag implicates super_saiyan (learn more).