@davidrevoy Honestly calling it a mimic is perfectly fine, because names are generally handled under trademark, not copyright, and trademark almost always requires that a mark not be 'generic' or 'purely descriptive'. And given that calling "a monster mimicking a thing" (treasure chest, chair, etc.) 'a mimic' is about as descriptive as you can get, any attempt at 'enforcement' would likely be grounds for sanctions against the lawyers that filed it with how purely-descriptive it is.

Now the term 'Hobbit' on the other hand, that was made up by Tolkien, and his descendants are dead set on keeping that trademark/copyright money-train going as long as they're legally able to, which is why almost everything else uses the term 'halfling' instead (which predates DnD by "a few centuries", and is thus also free to use)