I thought this card was super neat as a kind of
Promise of Bunrei stapled to creature but as I read it more closely I realized that it has to di during combat for you to get the tokens. I agree with StormEntity that having this thing die to something like
Shock would feel really bad. I'm all for including some cards that can die and not give you any value but I feel like they have to be a lynchpin of an archetype for that to be the case.
For example, I would be fine with
Titania, Protector of Argoth because it's so unique and enables something entirely new even though it dies to
Lightning Bolt and
Doom Blade without giving you any value. I know you can play it one turn 6 with a fetchland in play but let's just ignore that for this example. Maybe a better example would be
Braids, Cabal Minion as that's a pretty unique, powerful effect that costs 4 mana and can be answered pretty easily at no detriment to your opponent.
Those examples are pretty high powered but I think the difference between those cards and Mongrel Pack are that they don't really serve as a lynchpin for the archetype. It feels like there's a ton of cards that do what the pack does in a way that doesn't set yourself up to be blown out. Things like
Sultai Emissary and
Pawn of Ulamog might have a worse Best Case Scenario but I feel like their Worst Case Scenario is much better as well as the Average Case Scenario.