Hi there I have a few tips for pet battlers in general but first of the Minfernal
This pet is easily the rarest one of the Kalimdor critters, and he only spawns in the Shatter Scar Vale. As to catching this one it helps to have Characters from different servers parked in the area, but watch out for the infamous spawn inside the trees, there's a small chance you can use an AOE fear to pull them out but its still a pain.Infinite Whelping
This one has a kinda wonky spawn area in Tanaris but is predictably in the tunnels of the caverns of time of above where Tick the world dragon spawns, this is another one where you might want to have a few toons camping for it, but with a friend who can port you to Dalaran it's not that bad.
Those are the two I had the most trouble with, but as a note for all the weather dependent spawners like the Baby Ape
and the Silithd Hatchling
it good to hang around for a few minuets after the wether effect starts for some reason it took almost an hour but I got my Silithd after almost 20 min, and then checked Strangle thorn and the rain was going there and apes spawned that might have been a huge coincidence but always check the other weather spots when one is up: just in case.
As for over all battles and leveling until 5.2 we're still able to use the Safari hat to level 1-25 so long as the pet can survive a hit from a high level world battle: but since that's going away in 5.2 I would point out the best way to level is to use the tamers: the best way is to use pets that are 5 levels lower than the ones you're up against then to destroy them with your 25s. This is probably the -fastest- way to level them and I have been able to narrow down my leveling time to just about an hour and a half with this method, granted there's a lot of flying but if the safari hat is equipped and your pets are leveling its worth the miles you put into flying them around Azaroth!
Oh and one tip on Battling: in the event if you accidentally kill the pet you're trying to catch or if they kill themselves with a move and the battle is still going on you can actually ALT F4 out of the game and DC yourself mid battle: when you log back in you will see the pet you battled with in front of you! So use that liberally for something like a Minfernal
And a Doodle of my Character with Hokisho her Dragon