Monster: The Grogan

A stone-jointed granite monster. Many were made hundreds of years ago, but they are now rare, often found in abandoned tombs and ruined wizard lairs. They were fashionable as magical guards before most sorcerers realised that they were more trouble than they were worth.

The Grogan is quadrupedal, an up-turned metre-wide demi-sphere sitting on four equally spaced metre long legs. Eight triple jointed stone blades lie on the compass points around the top of the flat surface. In the centre of the body is a small pedestal, upon which sits a great stone eye with a black diamond pupil.

The Grogan is constantly in motion, and every movement sounds like nails down a blackboard. It dodges attacks and resists damage. The great and powerful stopped creating them when, inevitably, a Grogan would start attacking the master it was supposed to protect.

(STATS AND SPOILERS AFTER THE JUMP)

The Grogan

AC: Chainmail+bonus (see below). 6HD, 32HP
Special: In combat, the Grogan rolls two d8s for initiative and takes the higher. If it has the highest initiative then it adds the difference between it's initiative score and the next highest initiative score as an AC bonus for the round. Natural 20s hit it as normal.
Edged weapons do half damage, regular knives and daggers only do 1 damage. If a strike from an edged weapon is unsuccessful there is a 25% chance it will break (unless it is magical). Crushing weapons do normal damage.
The Grogan has up to three melee attacks (depending on the number of attackers) and slashes with the stone blades, each doing d6 damage. (only has a +2 for each attack, not +6)
It is not fooled by any illusion or invisibility spells, never sleeps and cannot be confused. It can see in perfect and magical darkness and has X-ray vision up to 20 feet.
The black diamond at the centre of the Grogan's eye is two inches in diameter. It is unbreakable and will come loose from the Grogan if it is defeated. Held in a person's hand it confers all of the sight abilities of the Grogan (but not the sleep and confusion resistance). However, for every minute it is held there is an increasing chance that the diamond will bond to the palm of the hand permanently. This starts at 20% and increases by 2% per minute. Roll to find out if the diamond has bonded when the person tries to put it down. If the diamond bonds, surgery or Dispel Magic/Curse cast by a sufficiently powerful person might remove it. Until then the person will have great difficulty holding a weapon or something else in their hand.
The right person, who knows what it is, might pay 50 to 100 gold pieces (LotFP standard) for the black diamond.