Board Thread:General Mod Discussion/@comment-26065088-20160516092258/@comment-26236093-20160516210854

Unfortunately, as High King Ithilion has said several of these creatures are intended to mentioned only in passing or serve as naught but bed-time stories for mischievous young Hobbits.

Another interesting point on the matter is that many of these beasts and creatures exist only exist in Tolkien's other writings (Roverandom, Amith of Wootton Major etcetera) or in what one would to refer to as Tolkien's extended writings which do have some correlation to Middle-Earth, but are considered to be simply fiction within the fictional work itself (for example The Tales of Tom Bombadil which generally only relates to Middle-Earth quite vaguely).

Also, several of these concepts were later abandoned as was mentioned above, with Tolkien wishing to move away from wildly imaginative stories and more towards the history of Middle-Earth and its peoples.

Furthermore, as has also been mentioned above several of the names of these creatures or the things themselves are quite often the result of Tolkien's use of poetic licence, more imaginative names being created to facilitate the rhyme and style of the poem. For example, it is quite clear that Hummerhorns and Dumbledors refer to some form of flying insect, with Dumbledor even being an Old-English word which refers to a Bumblebee.

In conclusion, though it is unfortunate it is likely that such creatures will be implemented not only for the reasons discussed above, but also as more important features shall take priority.