The easiest way to catch one is to invest 1 hour to level a DK on a really low populated RP server, since the pets are account bound. Choose a PVE server, so you cannot be attacked by a higher level player while having a pet fight. Create a DK, get through the starting quest until you get to OG or SW, then simply take the flight point next to the taming area.
With this toon farming other rare pets is also easy as hell since the servers are empty like the Silithid Hatchling and Minfernal.
Get yourself a map addon like SexyMap (http://www.curse.com/addons/wow/sexymap) where you can maximize the size of the minimap so you don't have overlapping pet trackers.