Head of Vecna
The Head of Vecna was a hoax started by an epic troll named Mark Steuer. During a session, he decided that he was going to play a prank on some of the players, so he had some of them (Group One) set up a trap for the rest (Group Two).
The Head was claimed to be the severed head of the arch-lich (and later god of undeath) Vecna. Like the Hand and Eye of Vecna, the Head was said to give the wielder incredible power over the undead. Also like the Hand and Eye, the Head was a replacement for the wielder's own body part. Members of Group One playing NPCs spread the rumor, while the rest set up a crude temple full of weak traps to guard it. However, a n00b Drood who came in late found the head before the other group, buggered off into the woods, and summoned an ape to cut off his head and replace it. He checked it for magical properties, and found none - then did it anyway. His fail was epic.
Group Two finally caught up after hearing about the item. Once they arrived at the location of the Head, they began arguing over who would get to be decapitated. After a few rounds of in-game fighting, one of them managed to win over the group and get his stupid gourd lopped off. One of the other players started protesting, but the Head of Vecna was placed on the ragged neck stump of the wizard that won the argument.
Then, predictably, it just rolled off.
Group Two decided they had waited too long because of the argument, and cut the next guy's head off. The replaced it quickly, and... it fell off again.
It was at this time that Mark decided it was too funny not to laugh and told them about it. The Head of Vecna was just some poor jerk's severed head, and there was no magic - which they could have figured out if they had paid attention. And, of course, HE got blamed for the whole thing.
TSR found this absolutely hilarious, and so the Head of Vecna actually appeared in their final 2e module, "Die, Vecna, Die!" alongside the other legitimate Fragments of Vecna. It was a classic AD&D style trap, and would be absolutely worthless to anyone who tried to add it to their own body; unlike the Heart, it would not bring a new host back from the dead.
Wizards, also found epic lulz in this and so, much later, someone decided it would make a great April Fools joke campaign, and worked it out as an official quest for 3.5. In the official quest, the Head is real, but horribly inconvenient in the fact that it has to be placed on a LIVING headless body, requiring a high-level spell (raise dead won't cut it) to bring them back. On top of that, the powers of the head are useless and cause permanent stat damage. All in all, a great way to screw with your party.
The powers of the head are determined by a d6 check when the head is attached:
- The head is powerless and the PC dies
- The head spins during combat, Poltergeist style, giving all around vision (no flat-footed or surprise attacks). After 2 turns, you have to pass a Concentration Check (DC15) to do ANYTHING. After 2 more rounds, the user falls prone, dizzy, and incapacitated. It takes 10 minutes to recover, and you lose 2 DEX until the head is removed.
- The head will spout useless opinions on irrelevant topics, and a DC20 Willpower check must be passed in order to do anything, otherwise the head takes control. -2 Charisma until removed.
- The user gets "rose tinted glasses" that cause them to see whatever they want. This means opening a Mimic's mouth will make the user see piles of treasure. -2 Wisdom until removed.
- The head will randomly swap with the heads of other creatures in the immediate area once attached successfully. The victims retain their original personality, NOT the one of the head they end up with. Anyone who's suffered this can swap for their original head, but not the Head of Vecna. ANYONE who has been the target of a swap loses 2 INT that can only be restored by a Miracle or Wish.
- The user gets two spell-like abilities chosen at random from the Wizard or Sorcerer classes (d6 for level, then pick one of the level from PHB). It's a once-per-day ability, it changes every day, and each time it happens the user loses two CON. Again, removing the head will fix it.
Case in point: check your source books.