An epiglottal or pharyngeal flap is not known to exist as a phoneme in any language. However, it exists as the intervocalic voiced allophone of the otherwise voiceless epiglottal stop/ʡ/ of Dahalo and perhaps of other languages. It may also exists in Iraqi Arabic, where the consonant 'ayn is too short to be an epiglottal stop, but has too much of a burst to be a fricative or approximant.
There is no dedicated symbol for this sound in the IPA, but it can be transcribed by adding a "short" (or non-syllabic) diacritic to the symbol for the stop, ⟨ʡ̯⟩. (The diacritic is here placed under rather than above the letter to avoid the ascender.)