Okay…ahem…I know this is fraught but since I was in university when Molten Corgi was released and was not then playing the game…and since I was not into pet battles at the time and never understood my folly until 8.3, when it was already too late:
I nominate the Molten Corgi for the next round of Drops promos.
Or at least put it on the anniversary timewalking vendor in the Caverns of Time. All the anniversary stuff should be on there not just the stuff from the last couple years.
I mostly use mine for capturing wild pokemon battle pets since it has Superbark (cannot reduce them below 1 hp). Puppies of the Flame is definitely nice though, especially for the predictable heavy hits.
Superbark is nice, but because it has a cooldown, it is not ideal. What you want is Weakening Blow. The easiest of these to get is the Terrible Turnip, and there is Stemmins, from Ardenweald, but both are squishy. I highly recommend going to the trouble of getting a Snobold Runt. You can buy one on the AH or farm one from Trial of the Crusader.