BOZ
Creature Cataloguer
that is a possibility, but hopefully that won't complicate matters up.
a few things to consider though: is making a Spot check during combat a standard action (even though that may not matter to the issue)? can't a character simply make a new Spot check every round anyway? if the character isn't intentionally making Spot checks (by stating, "hey, i bet something is hiding out there making our cleric sick so i'm going to look") does the DM even have to let them get an initial Spot check?
spotting the vampire moss isn't the worst thing in the world anyway. unless you know what it is, you wouldn't even necessarily know it's the one attacking unless you put two and two together. if anything, i would restate the camouflage ability to say that the initial chance of Spotting it is DC 20, and to notice the color change thereafter would be a DC 20 with a +1 cumulative bonus per round.
let me give an example to illustrate. the cleric from a couple paragraphs get sick. the fighter thinks there might be an attacker hiding in the woods and rolls a Spot check, getting a 21. the DM says there are no creatures out there, but this area does seem to have some odd moss hanging from a tree. not sure what to make of that, the fighter keeps spotting. next round he rolls a 13, notices nothing (DC 19). the next round he rolls a 19 on a DC 18 check and the DM tells him that the mosses is noticably brighter green.
a few things to consider though: is making a Spot check during combat a standard action (even though that may not matter to the issue)? can't a character simply make a new Spot check every round anyway? if the character isn't intentionally making Spot checks (by stating, "hey, i bet something is hiding out there making our cleric sick so i'm going to look") does the DM even have to let them get an initial Spot check?
spotting the vampire moss isn't the worst thing in the world anyway. unless you know what it is, you wouldn't even necessarily know it's the one attacking unless you put two and two together. if anything, i would restate the camouflage ability to say that the initial chance of Spotting it is DC 20, and to notice the color change thereafter would be a DC 20 with a +1 cumulative bonus per round.
let me give an example to illustrate. the cleric from a couple paragraphs get sick. the fighter thinks there might be an attacker hiding in the woods and rolls a Spot check, getting a 21. the DM says there are no creatures out there, but this area does seem to have some odd moss hanging from a tree. not sure what to make of that, the fighter keeps spotting. next round he rolls a 13, notices nothing (DC 19). the next round he rolls a 19 on a DC 18 check and the DM tells him that the mosses is noticably brighter green.