Crystal Coconut
The Crystal Coconut is an extremly powerful item in the Donkey Kong series.
In the TV Series
The Crystal Coconut first appeared in the Donkey Kong Country TV series. Its history on the show was that it was stolen from an unknown source by the great-great-grandfather of one of the show's main characters, Kaptain Skurvy. Skurvy's great-great-grandfather hid the Coconut on Kongo Bongo Island, specifically in the eye of the mystical idol Inca Dinca Doo. However, after many years the coconut pops out of it's hiding place and is found by Donkey Kong, who is then proclaimed the future ruler of Kongo Bongo Island. The show's main antagonists King K. Rool and the aforementioned Kaptain Skurvy constantly try to steal the coconut from the Kongs; the former wants to use it to take over Kongo Bongo Island; the latter believes it is his birthright as his ancestor stole the Coconut, and seems to want to use it to "rule the seven seas" as well.
The Coconut's powers in the show range widely. It is known to be able to heal wounds, and occasionly characters can look into it (like a crystal ball) and see whatever they wish to. Occasionly the Coconut projects images on its own, often warning the Kongs when Kaptain Skurvy and his crew are returning to Kong Bongo Island (this may suggest that the coconut posses some level of intelligence). Cranky Kong seems to be able to use the coconut to teleport (in an astral form) to different places, though he must always retun to where the Coconut is, even if it has been removed. For the duration of the show, the crystal coconut is kept in Cranky Kong's Cabin, inside a globe.
In the Games
In Donkey Kong 64, Crystal Coconuts were used as power sources for each Kongs' special ability. For example, Donkey Kong's Strong Kong ability allowed him to become invincible, but used up Crystal Coconuts. They were semi-common items that could be found in most levels.
Crystal Coconuts also appeared in the game Donkey Kong Barrel Blast. They are one of the items that come out of red balloons. If the player gets one, they will be invincible and have unlimited Wild Moves.