Quote Originally Posted by sandmote View Post
I'm not really familiar with 3.5e monsters, but this seems highly excessive for something CR 4. I'm imaging some lich capturing one to teleport into the middle of a major city.

I'd maybe up the CR and quantify the spread of the cloud of gas.
I know, I know. It is a profoundly unusable monster (except maybe as a plot point). The reason why would be that I tried to replicate the abilities/characteristics of an actula creature of folklore which is inherently and ridiculously unbalanced (a couple unarmed miners can kill it with relative ease while underground but it becomes a weapon of mass destruction (seriously, I'm not making this up (heck, I even scaled down its destructive potential a fair bit))). (Also, rest assured: 3.5 is crazy but not this crazy.)
As for the spread, well, there are spells with areas measured in miles (Eclipse comes to mind, with its 5 miles radius), so this is more of a balance problem (those spells are, of course, epic spells) than a problem of stuff being poorly quantified.
Should I, perhaps, put a disclaimer on the thing (WARNING: this is horribly unbalanced and that on purpose! Do not try to use this unless you can make it make sense!)

Edit: I really like the harvestman though. A mechanical "creep out" effect is really neat, particularly because I think the players would assume they're going to get jumped by something else while dealing with it.
Thanks! I'm happy to hear that!