Severed Heads

Talking severed heads are a great and memorable way to insert NPCs into your dungeon. They help add to the weirdness of the underworld, you can put them in strange places and they raise questions. Which is always a good thing.

Why is there a talking head here? (1d6)

1.  A wizard once wished for a demon to allow him to "throw off the shackles of my mortal body but preserve the greatness of my mind".  Now he's just an immortal, impervious head.
2.  It's actually a small, young shape shifting creature.  It heard people coming and, despite its best efforts to appear human, could only manage to form a human head.  Lies and claims it's a curse by a witch or something.
3.  A reverse Highlander (Lowlander?) that can only truly be killed by cutting off their... never mind.  Point is, they played dead after being decapitated and have ended up in this dungeon.
4.  Combining teleportation spells and permanence charms leads to a power to infinitely teleport, right?  This severed head, with the rest of its body trapped in the dungeon floor, will tell you otherwise.
5.  A victim of the Executioner of Bemyr.  His terrible ensorcelled blade brings the pain of severance and the guilt of past sins, but not the mercy of death.
6.  A head kept alive and controlled by the intelligent, insidious parasitic insects crawling within.   

Well, okay, what can they do for me? (1d6)

1.  It knows where the best treasure is.  Simple as that.
2.  It can whisper the words of great and powerful sorcery.
3.  They can give you some excellent dirt on a powerful figure/monster within the setting/dungeon.  This can include its one weakness.
4.  The head can regale you with the tale of a powerful enchanted object and where to find it.
5.  It can transfer and teach one useful psionic discipline.
6.  It has some hidden power (gaze attack, laser blast, etc.) and would gladly let you carry them around and use it on a foe once.                                           

Wait, do I need to do something for them first? (1d6)

1.  "Avenge me!"  Kill a target.
2.  Bring it some expensive and fine wine.
3.  Beat it in a game of riddles.  Yes, it's one of THOSE types of dungeon denizen.
4.  They remember the stars and wish to gaze upon them for the rest of their days.  Find it a good and safe spot, like an observatory or something. 
5.  They would like a fancy hat or crown.
6.  Get it a body.