#eternalize

You can’t do this for a couple of reasons:

First of all, you can only activate an Eternalize ability of a card in your graveyard any time you could normally cast a sorcery, i.e. in your main phase with the stack empty, so you can’t do it in response to anything.

Secondly, even if you could Eternalize the creature in response (which you can’t), the creature card is the only target of the Scarab God’s ability and so removing it from your graveyard before the ability resolves will leave the ability with none of its targets being legal and thus cause it to be countered when it tries to resolve. (This is what would happen with creatures like Scrapheap Scrounger or Reassembling Skeleton that can return to the battlefield in response.)

Eternalize, the Better Megamorph

Another massive Grand Prix Las Vegas is in the books, and it brought with it a pretty hefty amount of spoilers. There’s a whole lot to digest between the Invocations, the new Afflict mechanics (which is a modular and keyworded version of [casthaven]Vedalken Ghoul[/casthaven]’s ability), the evolution of Exert to tap abilities, the awesome design of [casthaven]The Scorpion God[/casthaven], and the…