Hoo boy. Just on its face, a 4/3 for 3 that punishes your opponent for using a kill spell on it seems pretty Standard playable, and the adventure pushes it over the top. Turn 2 Stomp into turn 3 Giant will certainly crush some bones.

Livewire Lash was a thing, you know? That's what this most reminds me of, but you can't trigger it, you can't choose who it hits, it only hits players (so no deathtouch synergy) and infect isn't in this Standard, so in many ways, it's worse.

It's good for limited and Standard, but probably not elsewhere.