MTG Salvation

So if that creature just happened to be Consuming Aberration

Its base P/T is defined by its rules text.

Base P/T has its own issues, since that includes clones, creatures with 0 toughness that ETB with +1/+1 counters (e.g., Spike Weaver, Arcbound Ravager, Phantom Nishoba, just sticking to some particularly famous ones from the past.), and 0 toughness creatures that get +1/+1 for each whatever, all of which will kill this instantly, provided you don't have anything boosting its toughness. So it's build around me, but you just might get a Death's Shadow too.

That's all just looking at older Magic critters. The biggest one I can think of right now is clones.

Would have been cool if it triggered on entering the battlefield as well, might have been good in some sort of through the breach deck.

Now The fact it can't block first turn nor be used with haste tricks makes it too weak, maybe as a sideboard card in some deck that only plays niv mizzet as a 10 power attacker.

Perfectly fine and fun bulk rare.

Begs to be built around, punishes you for putting four in a deck by flipping the other copies of itself and becoming a measly 3/3. You could Thud this to the face for 25 damage with the help of Ghalta, Primal Hunger, given you can keep this thing alive for a turn or a few turns until you flip the dino (nearly impossible in a creature-removal-centric standard, but sometimes they are holding something like Settle the Wreckage or Seal Away.) Not bad in commander if you're looking to just beat in with big dudes, but doesn't benefit from Best Keyword Haste.

I like it! Brings out the Johnny in me.