Super Ultra Holy Water
From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
The Super Ultra Holy Water (スーパー 超 圣水, Sūpā Chō Seisui; FUNimation "Ultra Divine Water"), Super Sacred Water, or Holy Water, is magical water that increases the drinker's strength substantially – if they can survive the poisonous and painful effects.
After Son Goku's defeat by Piccolo Daimao, he turned to Karin for a way to avenge the loss of his friends. In the manga, Karin gave him the Super Ultra Holy Water directly, while in the anime he transported Goku using one of his magic pots to an icy maze to the north where the Super Ultra Holy Water was kept. Moments prior to Goku being sent through, Yajirobe was looking for food and inadvertently fell into the same pot that would send Goku to the maze. After navigating to the Cave of Darkness together, Yajirobe and Goku parted ways. Goku soon encountered an illusion (created by Darkness) of Muten Roshi and all of his friends. They claimed to be hiding there from Piccolo Daimao. He fought "Roshi" and was almost defeated before his persistence convinced Darkness that Goku was worthy to drink the Super Ultra Holy Water (during the battle, Goku was reunited with Yajirobe again).
Upon drinking the Super Ultra Holy Water, Goku writhed in agony for some time and his whole life flashed before his eyes. After he had endured the pain, his increase in power was great enough that Karin was able to detect it from Karin Tower. This newfound strength was crucial to Goku's defeat of Piccolo Daimao shortly thereafter.
According to Darkness, the Super Ultra Holy Water was sacred and not meant for Humans. Later, he stated that thirteen people had drank the Super Ultra Holy Water before and none had surivived, making Goku the fourteenth and only known survivor up to that point. Since Goku was the only stated survivor and a Saiyan, it is unknown if any Human could actually survive its trial. It is possible that his Saiyan heritage actually played a large role in his survival, which would explain the Great Ape appearing just after Goku's power increased and just before he killed Piccolo Daimao.
 Video games
It is a treasure item named Mystic Water in Dragon Ball: Advanced Adventure. If the player finds it, they will be able to use it.
In Dragon Ball Z: Budokai Tenkaichi 3, drinking the Ultra Divine Water in the Sim Dragon mode levels your character up and gives them a huge increase in strength (just as it normally would).
- It was via the Super Ultra Holy Water that Goku first learned the Ki Sense ability; he remarked about this newfound ability to Karin when he stated that he knew where Piccolo Daimao was at. It is unknown how the rest of the Z Warriors aquired this ability.
- It is believed by some that Kami is somehow connected with the Super Ultra Holy Water due to his symbol actually appearing on the pot containing the Super Ultra Holy Water before Kami himself appears. It is likely, however, that all Guardians wear the symbol (as evident by the fact that his sucessor, Dende, was also sometimes portrayed wearing it).
- Yajirobe dipped his finger into the Super Ultra Holy Water and tested it before Goku drank it as he thought it was poison. It caused him painful effects for a few seconds, which led him to urge Goku not to drink the Super Ultra Holy Water. As Yajirobe did not die after sampling the water, it can be assumed that the Super Ultra Holy Water must be drank in larger quantities to either kill or improve the strength of the drinker.