I'm not sure if this feels expensive, because in any non-constructed format it sucks, or just about right, because in any constructed format, it'll net two creatures.

It's probably correct.

Finally a pull card that is interesting. I don't think I've ever used cards with similar effect since the old ones in the core set for green that did for 5?

Reviewing this card; does green do draw/discard? Most of the green draw filter spells I can recall put the cards on the bottom of the library.

If this is a hint towards a future mechanic then I can see it but if not, I'm not sure how 'green' this is.

It's pretty green.

I think Beast Hunt is the most recent example.

I was getting that tweaked with Call of the Gargantuan and Lead the Stampede.

I suppose it could go either way.

I think it really comes down to how much emphasis is to be put on the graveyard. "Test" is suggestive of somehow caring about your graveyard, but it's not a fully formed theme by any stretch of the imagination.

I think you can shorten this a little to:

"Reveal the top 3 cards of your library. Put a creature card from among them into your hand, then put the rest into your graveyard. If that card is a Wizard card, put a 1/1 green Snake creature token onto the battlefield."