A Chicken McNally is a more specific case of a McNally. The Chicken McNally is a McNally that is more likely to be made out of chicken (although it does not necessarily have to be chicken, since this term is most commonly used when stoned.)
Melvin: Dude, are those Chicken McNallys?
Rod: I don't know what they are, but they're really good, man.
Rod: I don't know what they are, but they're really good, man.
by defenestrator March 22, 2005