U+1D93 Latin Small Letter Open E with Retroflex Hook

The Wikipedia has the following information about this codepoint:

Latin epsilon or open E (majuscule: Ɛ, minuscule: ɛ) is a letter of the extended Latin alphabet, based on the lowercase of the Greek letter epsilon (ε). It was introduced in the 16th century by Gian Giorgio Trissino to represent the pronunciation of the "open e" (the letter e pronounced as the open-mid front unrounded vowel) in the Italian language; this use of the letter has since become the standard in IPA notation (see § Use in phonetic alphabets, below). Since the 20th century, the letter also occurs in the orthographies of many Niger–Congo and Nilo-Saharan languages, such as Ewe, Akan, Lingala, Dinka and Maasai, for the vowel [ɛ] or [e̙], and is included in the African reference alphabet.

In the Berber Latin alphabet used in Algerian Berber school books, and before that proposed by the French institute INALCO, it represents a voiced pharyngeal fricative [ʕ]. Some authors use ƹayin ⟨ƹ⟩ instead; both letters are similar in shape with the Arabic ʿayn ⟨ع⟩.