I've got a true wild fermentation going currently. I used a sourdough starter, pitched the liquor into a sugar water mixture and let that ferment for a few days until i was sure it was doing "something" and not just making acetic acid or lactic acid. I pitched some of that into Malta Goya mixture and let it ride.
Observations:
*No true krausen. It is basically like everyone is saying. It looks like there's something, possibly "slimy," on top but not a true, bubbly krausen like you'd expect from pure ale yeast. It varies from day to day a little but, since I am stirring it about 2 times per day, I don't know what it would look like if I let it go longer than a few days.
*Lots of floccuation. There's a ton of stuff falling out of suspension. I don't know what it is, but there's a lot of it.
*Funky smell. It isn't bad, per se, but it is funky. It is alcoholic as you can smell an alcohol edge to it but it isn't yeasty, either.
Again, this is a yeast / bacteria mix I picked up in my kitchen and not something you're likely to duplicate 100% from "true" bugs. It does sound suspiciously like what I've read a bug mix will get you, though.
Hope that helps!