Ƈ

Ƈ is a letter of the Latin alphabet, derived from C with the addition of a hook. It is used in African languages such as Serer.
The minuscule ƈ was formerly used in the International [Phonetic Alphabet] to represent a voiceless [palatal implosive]. It was withdrawn in 1993.
In Unicode it is U+0187 and U+0188.
These letters are contained in the normative part of DIN 91379: "Characters and defined character sequences in Unicode for the electronic processing of names and data exchange in Europe, with CD-ROM".