Might: 2*
Nature: 7* (Playing, Flowing, Burning)
* but see below

14 Weapons: Fluidity: +2s to Defend.
Kill: 10. Weapons: Magma Pseudopod: +1D to Attack, +1s if an attack is successful vs. metal armor. Born of Fire and Rock: +1s to Defend.
Drive off: 7
Flee: 4

instinct: Copy the form of what you face.

Special Manouver: Fission. The magmoeba divides in two. Split the total Nature of the creature between the two new, ever more humanoid, forms, and increase each new blob’s Might by 1. Remember to divide the disposition hit points between magmoebae. Treat Fission as a normal Manouver otherwise. It need not be successful for fission to happen.

Special Knock-out: Fusion. When a magmoeba’s hit points are reduced to zero, if there is another creature standing, the defeated magmoeba is forced to merge with another, becoming cruder in form. There is no additional change in hit points, but the merged creature reduces it’s Might by 1 (to a minimum of 2), and gains the defeated magmoeba’s Nature back.

When a Young Lord of Fire made sport with a Young Lord of the Earth, such was the fury of their coupling that a great volcano destroyed human civilization almost completely. Their seed, commingled, became the odd creatures known as “magmen” to most, but more properly magmoebas, for they are genderless blobs of silicoid protoplasm much of the time.

When first encountered, the creature is a large blob of magma-like appearance, perhaps resting in a pool, or feasting on radioactive rock. When a party engages it in some form of conflict, however, it wants to play, and will first use it’s Fission special Manoeuvre to split into two blobs of more humanoid appearance. It will keep doing so until it has aped the whole party.

Capturing a magmoeba provides an alchemist or smith with an abundant source of heat that is near limitless (the creatures consume fissiles that last a very long time). Killing one reveals their bizarre intellects are housed in a crystalline matrix of small diamonds. Occasionally a much larger stone is found. The gems may (or may not) be cursed to cause sickness, as they could be highly radioactive.

Unfortunately for adventurers these playful, unaligned blobs burn as hot as the molten rock they’re made from, so play time can be a lethal experience.

This is insane! Cool.

So, let me get this straight - when you first meet it, it’s a blog with Nature 7 and Might 2. As you fight it, the blob splits into successively more human-like fractions, each with a lower Nature but with an ever higher Might?

If allowed to split unchecked, the party will eventually be fighting seven of them, each with Nature 1. Two will have Might 5, five will have Might 4.

(You might want to make starting Nature a power of 2, to make the splitting and merging less irregular. Nature 8 means you’ll be fighting eight of them, all with Nature 1, Might 5.)

Can they all split at the same time, or only the acting portion?

I think only the acting blob splits, although I would buy that helping magmoeba could split.

You would only get 7 humanoid magma men and women if they were facing a party of seven.

The players have one major advantage if they get lore about these creatures or are observant. Namely that it is in the magmoeba’s playful nature to match the party as closely as it can before playing with then. i.e. it must Manouver at the start of conflicts.

Although these are extremely dangerous creatures, trying to loot a blob of living molten rock is not always going to go well. There’s lots of room to improvise weapons with waterskins and so on.