What is "agbirigba"

Agbirigba is a cant (or argot) based on the Ogbakiri dialect of the Nigerian language Ikwerre of Port Harcourt. There are about thirty speakers, from a persecuted section of the community.

Agbirigba is unintelligible to other speakers of Ikwerre, but the rule for its derivation is simple: the consonant t is added before every CV syllable (or, more accurately, every CV mora). Some speakers add an epenthetic vowel to break up the resulting consonant cluster.