Hello! So I’ve been looking around, and while I find a lot of suggestions on designing sentient alien species, I’ve found very little advice on how best to design alien fauna. I intend to have a creature as the focal point of an adventure, a kind of solitary hunter that drains energy from living creatures (and is capable of storing and moving that energy. I can grab one of the creatures from the corebook to use as a template for the stats, but this thing in particular sounds like a unique special ability I’ll have to write up. Any thoughts on how to go about that without going overboard?
The simplest way would be to just spend Threat (maybe on an attack) and say that the creature has siphoned some energy. If this should negatively impact the characters (maybe siphoned energy makes you tired and thus every Task is more difficult), then it would be basically the same as a Complication. Complication usually costs 2 Threat. This is how I look at it.
So you could say that for 2 Threat, the creature drains energy from a victim. This alone would be totally fine within the rules of the game. Of course you could do a lot of fine tuning and say the creature must make a successful attack first. Depending on how well PCs can defend against such an ability, you can even lower the Threat cost (or remove it entirely depending on how much of a boss this creature is supposed to be).
I found it quite beneficial to have the animal/aliens quite fluid (not in a changeling manner).
For example, I have my players exploring the McCallister C5 Nebula; their ships have been retrofitted with adapted shields to withstand the metagenic radiation, although it’s not perfect. Anyway - off the cuff, I decided that there would be swarms of a space-dwelling life forms, stats based on the Targ, they would be able to eat anything and possessed almost an antimatter-like stomach; whatever they are, produced energy for them. They had no need to breathe, as the thin gases in the nebula sustained their alien biology. An away team was exploring a derelict, ancient vessel, and they encountered these aliens; I had pictured them more like an insect version of Phantome from Voyager, but as I was describing their appearance, one of the players said “like a hormagaunt or a genestealer?” which then became their appearance (accidentally). They weren’t meant to be a huge threat, just a scary annoyance, but they were meant to scare the players off. I spent a Threat, as i had decided Stun would do nothing, and higher levels would wear them down (they are space based, so resilient). As the players weren’t getting the hint to withdraw, I decided to spend another Threat to also make them regenerate.
And now I have a mostly formed alien creature, from a basic idea and a bit of roleplay/reaction.