One of the most annoying monsters

...in Castlevania, at least. 

Sorry to disappoint Jeff, no duck/dragon thingies, back to the Castlevania monsters for me!  And I present the dreaded Medusa Heads!

Medusa Head
Armor Class: 1 (19)
Hit Dice: 1*
Move: Fly 90 (30)
Attacks: 1 bite
Damage: 2d4 + petrification
No. Appearing: 3-24 (3-24)
Save As: Fighter 1
Morale: 10
Treasure Type: L
Alignment: Chaotic
XP:13
Medusa Heads are floating humanoid heads with writhing snakes for hair.  They fly in erratic patterns, making them hard to hit, but also limiting them to only attacking every other Round.  A victim bitten by a Medusa Head must Save vs. Turn to Stone or be petrified, with all equipment carried, for 1d4 Turns.  After that time, the victim returns to normal.  Medusa Heads sometimes carry gems in their mouths.  It is unknown why they do this.

[Some DMs may wish to count Medusa Heads among the Beholder-kin.]