The Gold Horror

A heap of gold beckons, glinting in the party's torchlight and magefire. Finally, a reward for slogging through all those orcs... They approach, eager to count the loot. But as the thief reaches for the first handful, it reaches back. With a crackling discharge of lightning chaining through the coins, the whole mound flows upward and the lightning strikes...
A Gold Horror is an magical golem that transitions from an innocent looking pile of coins into a flowing swarm of coins in the air, linked by a network of lightning-like electricity. When fully coalesced from its ambush form, it will have a vaguely humanoid form, 7 feet tall, with coins spinning and swirling throughout.

H.D.	6-9, usually 7
A.C.	0(old) or 20(new)
Move	6"/9" charge
Init Bonus	0

Attacks & powers - use one mode per round
Shock - electrical discharge to 30', 7 dice, save vs dragon breath (or a CON/fortitude save in other systems), costs it 1D6 damage to itself in lost energy
Throw Gold - 1D6 gold pieces are accelerated to very high speed, 1D6 damage each, range 90', can pick target for each.
Infiltrate - can pass through any narrow gap that a coin could slide through, changing shape into a sheet of flowing coins, and reconstitute on the other side, takes a full combat round
Batter - Balls up a pseudopod fist/cosh and hits with it for melee impact damage. 2D6 impact + 1D6 shock.
Steal gold - a network of lightning enwraps a character within 10 feet, shocking for 1D6+2 (CON/fort/dragon breath save to take half damage) and gathering around and bursting one container carried by the character that has coins in it, all the coins and other small metal items animating and merging into the Gold Horror, other contents scattering around in an area up to 10 feet away. This heals the Gold Horror for up to one point per hundred coins it siphoned away, growing it by 1 hit die per 400 coins if there is more than enough to heal it. It can do this on any round in which it rolls a 4-6 on initiative.
Defenses
Electrical attacks against the Gold Horror charge it up, healing it instead of damaging it. Any extra it discharges back at a target within 30 feet or crackles away in a lightning discharge.
Immune to Charm/Fear/other mind-affecting spells
Immune to normal weapons and missiles, and 2D6 shock damage transmitted back along metal weapons to the wielder, with a 1/2 chance of weapon destruction.
Magic weapons and missiles do full damage, with a chance of being damaged - roll 1D6 per plus to hit, if all are sixes, the weapon loses one point of to hit or to damage bonus, and a point of INT if intelligent.
Vulnerable to water(grounding), cold, or grounding on planted or anchored metal.
Treasure: A Gold Horror doesn't have treasure, it IS treasure, once you kill it.The Gold Horror will be a mix of coins, 1D6 times 100 coins per hit die, at least half gold, with the remainder a mix of whatever other metal currencies your game uses. Plus, of course, whatever it has added to itself by looting your PCs.