You sit down and eat the delicious table tater, filling yourself with the energy of your homeland's beloved staple food alongside the still novel taste of cheese. While vaguely hoping the table was clean enough to eat off of. You review the information you totally know about the tooth in your head, without double checking with any of the multiple information sources that are nearby due to your high confidence in your own knowledge, then casually remark on the high freedom content of your lovely snack.
「You're not really free until you burn your Eight-Knot. In your case it should taste more like a breath of fresh air before delving back into the hill or something. Come on oh mighty Errant, we've got business to do. My parents where not in the sport of monster-hunting, and I'm not sure what they teach at that fancy medical school but I'm betting my beard it also doesn't involve sniffing down targets.」
With the GM stopping being cheeky, you recognize the tooth as belonging to a SkinCrawler. SkinCrawlers are on the lower end of Skinwalkers. They're angry spirits like those the Beast Folk deal with taking hold of some discarded carcass and causing trouble with it. They're a pretty rare occurrence, Spirits are uncommon on their own and most tribes you learned about make a habit of butchering monster remains in a way that doesn't leave anything it can latch on to. To be more specific the tooth is clearly a Starwolf tooth, but Starwolves are known for their powerful jaws that can break through armor as easily as you are biting through this tater. The only way something as frail as a Red-Lipped leg could possibly break off multiple teeth is if the skull has decayed to the point they where already falling out.
SkinCrawlers are typically made opportunistically, when a roaming spirit comes across the available material. As such it is usually in a significantly physically weaker state, with all the damage from their death and any decay that has set in after. However they are now capable of using spirit abilities like Beastfolk. The most common is casting curses. Usually this is done by locking eyes, but given the state the corpse is likely in it probably had to resort to using the bite. In all likelihood this curse will allow the Spirit to take a new host becoming a higher-tier threat, something resembling an evil Beast-folk that likes killing other folk. That is why even the Red-Lip's knowledge of the local plantlife was unable to defeat this 'disease'. You can stop this curse by killing the SkinCrawler thus banishing its Spirit, which is why your beloved partner is rushing you to do just that.