Maybe there's another Blazing Shoalbased deck or combo that could be scary, although it seems like it would have the same problem as Shoal Infect (needing to play a bunch of expensive, uncastable cards to make Blazing Shoal work)
While many of the new cards from Ponies: the Gathering 2 translate pretty seamlessly to MTG play, some of the older ones use some terms like Everypony that may be a bit loose in translation
Muldrotha, the Gravetide is the apex predator in this space
It's useless in the wrong deck, but if you can manipulate your top card, it's a super efficient means of drawing cards
A creature that rewards players for attacking with non-humans could be a risk in a set with no human creatures
Some sort of at least basic looting effect would have been good, but without it you need some other way to discard cards to then get the buff, and Howler has no way to take advantage of the buff themselves (no evasion), so maybe you want to target something else