Golems come in a wide variety of materials, forms and shapes.
To qualify as a golem there must be a form (it doesn't have to be humanoid, animals are sometimes used in the case of Homunculi.) And the form gets a primitive AI injected through magic. Through the AI the golem can follow simple commands, like "follow", "stay", "attack", "guard" and other simple commands.
The Ytarrans were masters of golem creation and through their research they were able to create the living constructs known as Warforged. Though the Artificers of Vistria were also able to pick up on that and are also very capable golem creators, it is rumoured that their progress may be because the Dark Ancients wanted more golem bodies.
Most golems have a DR based on the material there are made of (0 DR for a spaghetti golem, 10 DR for a Clay golem. There has been no Spaghetti golems in TDDC but I'm sure Draven will get to that eventually.) Not all golems in the setting are immune against magic (of course there are exceptions like the Psion killer golem who would not be able to kill Psions effectively if he wasn't immune against magic.) But instead have spell resistance.
All golems have abysmal will saves because there are immune against most things that would require a will save (though Little One's Disrupting Strike ability is one of the few things that has shut more than a few golems down.)
There are also immune against poison, sleep effects, paralysis, stunning, disease, death effects and Necromancy effects. They cannot heal damage on their own and must be repaired.
Normally they cannot be affected by Critical hits, nonlethal damage, ability damage, ability drain, fatigue, exhaustion or energy drain.
There are many types of golem in circulation, due to both the high number of potential materials and the many designs avaliable to the canny artificer. A small selection is given below:
Clay golems are golems made from clay. As a result of this, they are more fragile than stone golems, but also faster, with the ability to cast haste. Beta used a trio of clay golems in his ambush of the party in Episode 22.
Stone golems are pretty sturdy, they are most commonly made from a single block of Granite or other hard stone. The party saw several normal stone golem's in Vistria but the only stone golem the party fought was a costum made stone golem (most likely created by Delta, with his Transmutation spells he would be pretty well fit too give the stone the fitting details.) The costum made stone Golem Delta fought in didn't have the special stone-golem ability of casting slow every two rounds as a swift action. Instead the costum made stone golem could "cast" the spell Great Thunderclap as a free action. The costum made stone golem was later destroyed by Little One in a fit of rage when Delta left it's body.
Corpse golems or Flesh golems are created from at least six creatures (two arms, two legs, torso, head and brain can come from the same creature.) Stitched or bolted together to create a large creature that resembles a human. Obviously you can also use more body-parts to create a golem that is brighter or has more arms but if you don't invest more spells in it, you will most likely not get additional benefits.
The only corpse golem the party fought so far, was in the same cavern that Benzegegoth was in, together with a Lodestone Marauder and some negative energy infused zombies they should have protected the Spirit shackle that was in there, but it got walled in by Draven and after it punched through the wall it got dispatched fast, with Little One's Disabling Strike Maneuver playing an important role to disable the golem.
The Psion Killer
As the name implies, this golem is designed to fight psions. It was found guarding a chest in a cave below the ancient Adar city of Eloyah, implying that it was designed by that venerable old nation. This supposition is backed up by the fact that, like so much of their technology, it is made from crystal. Unlike most golems, which are only resistant to magic, these golems are immune.
These golems were made by the long lost Ytarrans; a people renowned for their magi-technical ability. The majority of Late Yttara's golems are made from Yttronium. Most of Yttara's golems were mass produced using a Creation Matrix, a type of extremely rare magical fabricator. As only the Ytarrans had access to Creation Matrices, this means that Yttronium golems are rarely ever found outside Ytarran facilities, such as Polaron.
Slicing golems, as the name implies, are designed to slice up enemies. They spend most of their time in the form of spheres, but when they attack they reveal a large number of incredibly sharp blades, which allow them to use a whirlwind attack (see image, right). When in sphere mode, they can move around quickly by rolling and also have a bonus to AC.
The Ytarran conducting golems were specifically designed to hold the bottleneck that at the entrance to Polaron. They are large sized with big shields that they can use to knock people into the big Death Laser that dominated the room. With their shields they could also angle the Death Laser so as to hit more individuals with it.
Game mechanics: The conducting golem has relatively high AC long with damage resistance of 10 and immunity to electrical damage. On its turn, it can either attack, bull rush enemies to knock them into the Death Laser, or angle the Laser with its shield.
Fire Suppression Units
The fire suppression system is specifically designed to fight fires in Polaron, a facility that had a significant risk to fire because it used large amounts of lava and elemental fire energy. The FSU looks like a standard Yttronium golem, but with a ice cannon replacing the right hand. The FSU is covered in custom patterns of ice crystals that make it very resistant to attacks and fire.
Game mechanics: The Fire Suppression Unit has a standard Armor Class of 26. Each round the golem regenerates two Ice points to a maximum of 7. Ice points grant the golem +2 AC and 5 fire resistance per point. You can get rid of the Ice points by missing the golem with an attack that would hit it's base AC, this breaks part of the ice and chips away 1 Ice point. The Fire suppression system can either attack with its arm cannon which casts the spell cone of cold and recharges 1d4+1 rounds after use or it can attack with an ice saber to it forms over it's hand to attack enemies.
The Ytarran artillery golem was constructed as a way to battle large groups of undead, because of its ability to carpet a large amount of space in destructive fire. The general strategy against undead was too have some artillery golems and some Fire suppression units, so that the fire the battlemech golems would cause would not endanger Ytarran units.
Game mechanics: On each of its turns the artillery golem could move and shoot one of its "missiles". Alternatively it can enter a special stability mode, immobilizing it and shooting 3 "missiles" in whatever pattern it likes. The artillery golem can shoot 3 different missiles: Glitterdust; a packet of energy that works just as the spell glitterdust but for 1d4+1 rounds, Demobilizer; a round that works just like a slow spell, Incendiary; a round that deals 2d6 fire and 2d6 bludgeoning damage in a area around the impact. At the end of each of the golem's turn it designates a target with a touch attack that gives them 3 Polaron charges. At the beginning of its turn (if it has designated a target) it shoots an artillery beam which deals 4d6 electricity damage and expends all charges on the target for 10 electricity damage each. The artillery beam can be circumvented if you block line of sight (flee around a corner) or line of effect (the beam would still hit whatever you threw in between you and the golem.)
Digging machines are Ytarran golems designed to dig tunnels. Physically, it resembles a giant grey worm with a green laser array it's front.
The Strategic Withdrawal Unit was designed so that Polaon Controller could retreat in a giant battle mech if the facility came under attack. The SWU was designed such that it could be launched into the portal room, the main atrium or outside of Polaron completely. When it was inevitably taken over by Epsilon, he launched it into the portal room as part of his recurrent "irradiate the continent to wipe out organic life" plan, but was defeated by the party. The SWU was destroyed in the process.