Once a month or so, we’ll do a Random Monster Mashup! This could take many forms – maybe see what happens when the monsters fight or team up, think about what kinds of circumstances might result in this situation, and even, if we’re feeling really creative, think about what happens if we stick these two monsters in a teleporter together and hit “SEND.”

The two monsters this month couldn’t be more different. The Iron Golem is solid and rigid, a construct against which your party’s attacks will break, and literally unchangeable by any means. The Water Elemental is formless and ever-shifting, able to squeeze through the tiniest spaces, with no shape other than the one it needs in that moment.

A head-to-head fight against these two is pretty lopsided – the Elemental is CR 5 and the Golem is CR 16 – but a summoned elemental could be enough to give your players an edge in a fight. The Water Elemental could use its Whelm ability to hold the Golem in place while your players attack it, though the Golem’s very impressive strength means that it would have to roll very poorly indeed for the Elemental’s trick to work. On the other hand, the Water Elemental is immune to poison, so the catastrophic Poison Breath that the Golem uses will have no effect on it.

Honestly, though, the fight between these two is far less interesting than what happens when you put them together in some interesting ways.

For example, what if the Elemental had been magically trapped inside a Golem, used to act as the construct’s hydraulics. This new hybrid creature could have been created for a singular purpose – a guardian or a weapon, perhaps. Or maybe it was an experiment that failed and was abandoned where no one but your Party would find it.

Here we have a creature of fluidity made rigid, forced into a form that it must maintain. What would that be like for this creature? Would it be grateful for the strength it has been given, of would it yearn for freedom, to dissolve back into the waters from which it came?

Maybe you want something more Steampunk – an Elemental in an unbreakable crystal tank by choice, held by a Golem of gears and armor. Some madman went and gave the ocean a pair of fists and unleashed it up on the world. Every time it moves it hisses with steam. It emits high-pressure jets of water that can cut through steel, or release a flood to drown all before it. With these two creatures combined, you empower both to become far more terrifying than they would be separately.

Ah, but what if your Elemental’s cage is cracking? An ancient Golem that has contained a spirit of water since time immemorial. As it carries out the battle it has been ordered to fight, the Elemental whispers in tiny bursts of shimmering mist: “Break it. I beg of you. Break it and I will show you the gratitude of the sea.”

There are some other twists on this combo that could be interesting. For example, what if the Golem is not containing the Elemental to use as a power source, but rather to contain its power? Within this great walking construct is a magically-preserved desert of absolute dryness, and held within that is the seed of a mad and vengeful Water Elemental. Destroy the Golem, and the Elemental is freed, able to draw on every water source around it to rebuild itself. Your players’ blood, for one.

Take this a little further, and you could have a walking ecological disaster. The Elemental inside the Golem is mad, draining water from everything it can in order to stay alive. As the Golem passes, rivers dry up, crops fail, people die. The Golem could be taking it to the sea, where the Elemental might finally be sated, but everyone in its path is doomed to become dust unless it is stopped.

For two creatures that seem to be so different, the Iron Golem and the Water Elemental complement each other wonderfully. One is containment, the other contained. One is unchangeable, the other ever-changing. Bring them together, and you give your players a choice: will they fight to keep the lid on something ancient and volatile—or break the seal and unleash what was never meant to be free? Either way, they won’t forget what it felt like when the cage started to crack.