The phrase pretty much describes itself.
A pagan yap is one who gets crunk off of a toke of fosters.
A pagan yap is one who become lean off one shot of otto.
A pagan yap accuses you of rape and then skets around.
A pagan yap is a yap, unwanted by the dons of south central UK.
Olly: 'What's crackin' fool? Chillin on my '64'
Pagan yap: 'BLACKBERRY!!! Tara gave me a handjob at butlins erhdgerfhjerfgbrftr'
Olly: 'Fucking skat.'