The Umli? Did/ do they exist?

[piosenniel]

The Umli are not a Tolkien created people. You can find their description in the Second Edition MERP (Middle-earth Role Play) book from ICE:

The Umli live in the Far North of north-central Middle-earth, east of the Lossoth. They are a race of short folk who apparently came from an ancient union of Men and Dwarves. Legends call them Half-dwarves.

Hunters, gatherers, and fishermen, they move from site to site depending on the season. Most reside in caves of underground settlements. Many mine, and the Umli are accomplished smiths and artisans.

~*~

ICE uses many interesting sub-groups for its Middle-earth role play games, some of which are from Tolkien works (though the powers they have may not be) and many of which are not found in any writings by Tolkien, as you can see from this list from a book on Races

Centaur - Horse Centaur; Lion Centaur
Droloi
Dwarves
Elves - Wood Elves; Grey Elves; High Elves; Linaeri/Loari; Dyari; Erlini; Half-Elf; Sulini
Fey - Dwelfs; Lennai; Tylweth Teg (Peries); Satyrs/Fauns
Garks
Gnomes
Goblins - Goblins; Hobgoblins; Kobolds; Murlogi
Gratar - Black Gratar; Gray Gratar; Green Gratar; Yellow Gratar
Halflings
Half-Orc
Hira'razhir - Hira'razhir; Hirazi
Idivya
Men - Common Men; High Men; Mixed Men; Laan; Jhordi
Mermen
Orcs - Common Orc; Greater Orc; Lugroki
Quishadi
Shuikmar
Sohleugir - Suarkar
Troglodytes
Umli
Urlocs
Vorloi
Vulfen