2. Name

You'll want a way to refer to the monster, at least in your own notes. Write it down.

If the monster has a proper name that it goes by, call it that, maybe with a short description. For example, "Sajra the Swyn" or "Daedre the Red, bandit leader." Pick proper names from an appropriate name list or almanac entry, or make up something similar.

If the monster is known to the people of Stonetop, and it's something they consider mundane or commonplace, then give it a simple, descriptive name in plain English (like "feathered drake" or "butcherbird").

If the monster is surrounded in mystery, a thing of rumor and legend, then give it a Welsh-sounding name (like "nailadd" or "ceffylwraig"). Come up with a word or description in English associated with the monster, then run it through an online translation service. Combine and tweak the resulting translation (or try other phrases) until you find have something that sounds good and is simple enough to use in play. (You can use this technique to come up with proper names, too.)

For monsters that are known to another people, like the Manmarchers or Hillfolk, use a similar process as above. But for mysterious, rumored monsters, translate the English description into a language appropriate for the people or region. If it's a mysterious monster known to…

… the Hillfolk, then translate it into Breton and drop some of the vowels, giving it a clipped, truncated sound.
… Marshedge, then translate it into Irish.
… the Manmarchers, then translate it into German.
… the folk of Barrier Pass, then translate it into Nepali or Tibetan.
… Lygos or the South, then translate it into Greek, Hebrew, Persian, or Arabic.
… the folk of Gordin's Delve, then decide which immigrant group originally named it, and translate it as above.
… other peoples (like the Ustrina), then consult the appropriate entry in Book II.

For monsters that are unknown and unnamed, give them spooky, descriptive titles in plain English, like "The Shadowy Presence" or "The Killing Frost" or "The Thing in the White Well."

Because Fae can speak with anyone, their names are more like phrases. I think my guardian Fae share a title, related to gifts or offerings and standing guard. I think a bit and write down: The Almtakers, guardian Fae.

The Forest Folk would have had their own (Slavic-sounding) name for the Almtakers, which folks from Stonetop might know. I play around with an English-Bulgarian dictionary, and find that "receivers" can translate to "priemnitsi." I like that: "the Priemnitsi."