Cche
Cche (Ꚇ ꚇ; italics: Ꚇ ꚇ) is a letter of the Cyrillic script. It was used in the old Abkhaz alphabets, where it represents the voiceless retroflex affricate /tʂ/. The letter was invented by baron Peter von Uslar. In 1862 was published his linguistic study "Абхазский язык". The letter is Ҽ-shaped but in 1887 Uslar's study was reprint by M. Zavadskiy who change its shape and resembles a Cyrillic Ч doubled. Later the letter returned to its initial form, created by linguist Uslar, is part of modern Abkhaz alphabet, which is depicted as Ҽ.
...
Wikipedia