Golem, Puzzle Complete (CR 12)
Alignment: Always neutral
Initiative: -1 (Dex)
Languages: Cannot speak
AC: 24 (-1 size, -1 Dex, +16 natural), touch 8, flat-footed 24
Hit Dice: 16d10 (88 hp); DR: 25/magic
Fort +5, Ref +4, Will +5
Speed: 20 ft. (cannot run)
Space: 10 ft./5 ft.
Base Attack +12; Grapple +12
Attack: 2 slams +19 melee
Full Attack: 2 slams +19 melee
Damage: Slam 2d8+8
Abilities: Str 27, Dex 9, Con -, Int -, Wis 11, Cha 1
Special Qualities: Construct, magic immunity, split, rebuild
Advancement: 17-20 HD (Huge)
Split (Ex): As a standard action, the puzzle golem can split into smaller golems, called "pieces." The complete, Large puzzle golem can split into two Medium-size pieces. A single Medium-size piece can split into two Small pieces. A single Small piece can split into two Tiny pieces. Tiny pieces cannot split into smaller pieces.
When split, each piece acts independently and uses the statistics for the appropriate size. A single piece will not voluntarily move more than 50 feet from another piece. If it finds itself beyond 50 feet from another piece, it moves toward another piece as its action. A piece cannot split if there is insufficient space for it to do so. Pieces do not have to split all at once - a Medium-size piece can split into two Small pieces, while the other Medium-size piece can remain at Medium size. The golem can remain in any form indefinitely, but it usually tries to assemble into its Large form after a battle is complete.
Rejoin (Ex): If a piece is within 5 feet of another piece of equal size, the two can merge together to create a single piece that is one size category larger. As a standard action, one of the pieces rejoins with the other, which must not move but can be in combat. Joining together creates a single larger piece with full hit points and none of the spells or effects (such as transmute rock to mud) that either piece had on it before rejoining.
To rejoin, a piece must combine with another piece of equal size. If a puzzle golem has a single Tiny piece destroyed, it can no longer rejoin to Large-size, because it lacks a required piece. If a piece is destroyed, every smaller piece that it is composed of is also destroyed.
Rebuild (Su): A puzzle golem can rebuild pieces that have been destroyed so long as the following criteria are met: it has access to a pile of stone equal in size to its starting form, there is at least one piece remaining, and it is within sight of the "ruined" pieces. A single Tiny piece can be rebuilt in one day and will then stand inert until it can be rejoined with a companion piece of equal size. The puzzle golem only rebuilds enough pieces to restore itself back to working condition - it cannot create "backup" pieces or an entirely new Large puzzle golem. Like with splitting and rejoining, a puzzle golem does this only under the direct command of its creator or when given explicit commands to do so when left alone.
Construct: Immune to mind-influencing effects, poison, disease, and similar effects. Not subject to critical hits, subdual damage, ability damage, energy drain, or death from massive damage.
Magic Immunity (Ex): A puzzle golem (including each of its smaller forms) is immune to all spells, spell-like abilities, and supernatural effects, except as follows. A transmute rock to mud spell slows it (as the slow spell) for 2d6 rounds, with no saving throw. The transmute mud to rock spell heals all of its lost hit points. A stone to flesh spell does not actually change the golem's structure, but it negates its damage reduction for 1 round. Each of these effects is negated (except for any hit points gained from a transmute mud to rock spell) if a piece of equal size rejoins with the affected piece.
Like other golems, puzzle golems are direct and single-minded in combat. The golem's creator gives commands as to when the puzzle golem should split and rejoin. Typically, in the first round, the puzzle golem remains in its largest form. After that, it breaks down into smaller individuals. With this tactic, the puzzle golem can handle multiple opponents or swarm and pulverize a single foe. Small and Tiny pieces try to grapple a single foe and aid the attacks of a larger piece, while the larger piece hammers away on the opponent.
If a single piece sustains half or more of its hit points in damage, it immediately tries to rejoin with another piece of equal size in order to regenerate. If individual pieces, but not the entire golem, are destroyed in combat, award XP based on the size of the piece: a Medium-sized piece is worth half the XP, a Small-sized piece is worth one-quarter XP, and a Tiny-sized piece is worth one-eighth the XP.