En-ge
En-ge is a letter of the Cyrillic script used only in non-Slavic languages. The shape of the letter originated as a ligature of the Cyrillic letters en and ge, but en-ge is used as a separate letter in alphabets.
En-ge is used in the alphabets of the Altai languages, Meadow Mari, Tundra Yukaghir and Yakut. In all of these languages, it represents the voiced velar nasal, like the pronunciation of 〈ng〉 in "sing".
En-ge was also used in two 19th-century alphabets for Aleut.
Ҥ is romanized using Ṅ, Ng, or even Ŋ.