Ravenous Squirrel from Modern Horizons 2 shows us that we're not just getting squirrels that play into tribal mechanics, but squirrel creatures that are legitimately good on their own and can be played in a variety of archetypes.
Ravenous Squirrel could be totally fine in a Squirrel tribal deck, as we have already seen some sacrifice mechanics on Chatterfang, Squirrel General. The fact that Ravenous Squirrel itself can be a sacrifice outlet and card advantage engine (though mana intensive) is just a bonus.
But of course, any time a 1-drop has a passive effect and ability to grow this much, we should take a closer look and see what can be done to break it.
For starters, in Modern we have several options that put +1/+1 counters on this essentially for free. Mishra's Bauble comes to mind, or perhaps a Carrion Feeder aggro shell. Could the Witch's Oven / Cauldron Familiar combo that dominated standard and seems to still be good in Historic be good enough for older formats? Is it possible to take advantage of the ability to sacrifice artifacts and work Ravenous Squirrel into some kind of Hardened Scales or Arcbound Ravager monstrosity? It seems like a somewhat challenging deck to build properly, but the power level is high enough to put in the work trying!