Minfernal and Scourged Whelpling. I haven't tried the RPPvP trick yet, though. Gonna have to give that a go.
EDIT: After creating a DK on an RPPvP server, farming up 2 gold, sending it to a level one and getting that to the Argent Tournament Grounds, I could FINALLY capture a Scourged Whelpling after checking in on the levle 1 character about a dozen of times!
EDIT2: Just after posting the first edit I found a Minfernal! It was a 7 but I made it rare with a stone anyway, never going back to Felwood again.