In Firelands for the Alysrazor fight there are two birds. It is possible to mount one bird, point it at the other and kill it. If both birds aren't killed they will both respawn... You will gain rep from this at least until Honored. While this may be more educational and interesting then useful it is an exploit nonetheless. It however will require dieing... unless vanish or feign death and the likes work... so it may be a costly "farm" as well. Like I said, may not be overly useful but still an exploit.