The Forbidden Fruit (3.5e Equipment)
From D&D Wiki
The Forbidden Fruit
"Knowledge is truly the greatest weapon, those who hold it can topple their enemies without so much as lifting a finger but some knowledge was never meant to be known... At least that's what the Gods and their servants will tell you. Many refuse this, claiming that all knowledge can be harnessed for the greater good. To them The Forbidden Fruit is the greatest of prizes, appearing as a faintly shining golden apple, the 'Fruit' is said to bestow those who eat it with knowledge of all things including that many claim is better left un-known."
The Gods and their servants work tirelessly to destroy every mention of these fruits and as such there origins are uncertain, what is known is that they originally grew on a tree and were then scattered throughout the universe. What isn't known is whether this tree still stands or how it came to lose its fruits; did they fall or were they plucked? If so whom and for what purpose? It may be only the fruits themselves can answer these questions.
These fruits are all roughly the same size and shape, usually considered to resemble a golden apple they appear to be entirely golden and give off a golden light. To those able to spend time inspecting the fruit they can tell that they dont seem to be quite ripe yet, pheraps being separated from the tree before they could grow to their full power.
To use the fruit one must simply take a bite out of it as they would an apple, this can only be done once per day. The character must eat the piece of the fruit, it then takes the following day for the fruit to 'heal' before it can be used again. This gives the user three effects, firstly the user gains all knowledge of one specefic creature which they know exists, the DM must give the player that creatures entire stat block as well as any information regarding that creature which relates to the user ('specefic creature' refers to an individual not a race or creature type). Secondly the user gains a +30 insight bonus to all rolls directly related to that creature for the next 24 hours. Lastly the user must roll 1d100 on a 1 they go permanently insane and can only be cured by a wish or miracle spell, on a 2-99 they take 3d4 temporary Intelligence damage. On a roll of 100 the user learns an intrinsic secret about the universe or a piece of information currently important to them, one may learn of the machinations of an evil deity planning to plunge the world into chaos a thousand years from now or learn where they left they're keys. The user decides which of the two to learn but the DM decides exactly what is actually discovered. A user can only learn about a specefic creature once, thus you cannot gain the +30 insight bonus on a specefic creature more than once. If a character attempts this they instead take 1d4 temporary intelligence damage and cannot use the fruit again for one day.
Ironically only mortals can destroy Forbidden Fruits, to do this they must simply keep eating them until nothing is left. Any mortal who does this will immediatly fall unconscious and die 1d3 rounds later, they're body will turn to dust and they're soul be destroyed making it impossible to resurrect them in any way. If one stops before eating the entirety of the fruit they will not die and the fruit will 'heal' after one day. It is impossible to cut or otherwise harm the fruit in any way and if the bites are spit out rather than eaten they will turn to dust one day later when the fruit 'heals'.