You're talking about an Irish vampire with bad teeth? You MUST be talking about Cassidy in Garth Ennis's 'Preacher' comic books. Talk about irreverent religion-lampooning BRitish humour at its best. Even if you don't read comics I would recommend everyone to read Preacher. It's probably the single best complete comic strip I've ever had the immense pleasure of reading.

http://en.wikipedia.org/wiki/Preacher_(comics)

(ha ha - the irony of me reccing something else is not lost on me at this stage.)