Looks to be about 35-40 feet tall or so judging by the people standing nearby. That's definitely a respectable size.
As far as the Cat-Snake.. that looks to have some serious potential in modern/legacy. In standard, it might squeeze into some side decks, but it depends on how potent counter magic is (usually isn't great nowadays).
I think this is a rare only because of how artifact heavy limited will be. Would have made too many waves as an uncommon in that format, even though that is probably the more appropriate rarity for its power level.
Because, if this were at instant speed, it would be a crushingly strong card if you were on the play.
Your turn 3 can put them down to 1 land and you've just potentially locked their hand down to win game, and before they even have enough mana for counters.
There are definitely more than a few cards in revealed so far that will likely see play in modern and legacy, and as far as the set seeming like it is all over the place, I am sure that a lot of things will come together more as more of the commons and uncommons are revealed. It is really hard to gauge the power level of the set as a whole when it revolves heavily around colorless cards, exile effects and tribal when there is still a lot of cards to be revealed.
Judging by the fact that there are at least a handful of cards that will probably fit somewhere into modern and legacy decks, I don't think it is anywhere near the worst set.
I am trying to figure out what numbers you are supposed to run with this in conjunction with the shock lands. These are definitely going to make building mana bases in modern a lot more difficult.
I'm counting what we're guaranteed and the immediate impact. It's very important that Ob replaces himself no matter what. In the CA game, he's always going to replace himself. His +1 draws a card and his -3 immediately 1 for 1's. It's a mathematical dream on an engine. But I mean I think you're agreeing so...I approve?
Not only that but he has 5 loyalty. Usually a good way of working out if a planewalker has a good amount of loyalty is if CMC = loyalty. The average seems to be about CMC-1 so being at CMC means he can tick straight to 6 making him very hard to kill with damage.
He isn't really a win condition but that ultimate can win the game in a pinch which is probably nice if things turn into a bit of draw go.
With all this power of course the drawback is if you tick up all the time you'll pay lots of life. Perhaps he fits in Abzan with Siege Rhino. I would say you'd at least want white for something with lifelink. Orzhov control is shaping up with all the best removal. Utter End, Valorous Stance, Swift Reckoning and of course all the mono black stuff which is obvious.
His ultimate is a pretty decent win con if you ask me. If he is still around after the ult, and able to use his +1 on the next turn, your opponent is going to be losing 6 life a turn, so realistically it puts them on a 3-4 turn clock.
5 CMC might keep this from seeing a lot of modern or legacy play, especially considering it can't really win a game on it's own relatively quickly, but it seems like a strong card for any deck that runs black and have any sort of control elements in standard. It has perhaps one of the best self-protection abilities out of any PW out there, high starting loyalty, and a +1 that is as close to always relative as possible. The ult is relatively lackluster, but essentially paints a clock on the enemy that will cause them to lose the game in anywhere from 5-10 turns maximum, so it isn't terrible.
The amount of card advantage that this card provides for black is astounding, and could possibly open up more possibilities for mono-black control in modern.
As many of already stated, I think proxies (of decent or higher quality) are perfectly fine in all manners except sanctioned competitive tournaments.
As far as those that take offense to people using proxies in casual or unsanctioned games(with the exception of poor quality, sharpie scribbled proxies), I think it is a tad bit asinine to be against it simply for the reasoning that you had to pay for the cards and they didn't. The value of the card and the comfort of owning the actual card should be enough. If you are here to play a game of magic, and the opponent has good quality proxies, then it shouldn't matter if they are real or not. It shouldn't have any affect on either you or your opponent's enjoyment of the game. Getting beat by a proxy deck is no different than getting beat by a $5000 legacy deck.
Also, for those of us that aren't made of money or have wealthy parents feeding our hobbies (which I am positive is a fairly sizable chunk of the MTG population), proxying is the only logical way of testing a deck out in real life without spending insane amounts of money for cardboard that you may decide you don't even like using.
I am surprised that Humble Defector hasn't made it into anyone's list. Not only is the potential for abuse real, and not too difficult to pull off, but even without being abused it seems like it may end up in the right red decks. Card draw is card draw for Red, and rarely does Red get any that doesn't also force a discard as well.
As far as the Cat-Snake.. that looks to have some serious potential in modern/legacy. In standard, it might squeeze into some side decks, but it depends on how potent counter magic is (usually isn't great nowadays).
Your turn 3 can put them down to 1 land and you've just potentially locked their hand down to win game, and before they even have enough mana for counters.
His ultimate is a pretty decent win con if you ask me. If he is still around after the ult, and able to use his +1 on the next turn, your opponent is going to be losing 6 life a turn, so realistically it puts them on a 3-4 turn clock.
The amount of card advantage that this card provides for black is astounding, and could possibly open up more possibilities for mono-black control in modern.
As far as those that take offense to people using proxies in casual or unsanctioned games(with the exception of poor quality, sharpie scribbled proxies), I think it is a tad bit asinine to be against it simply for the reasoning that you had to pay for the cards and they didn't. The value of the card and the comfort of owning the actual card should be enough. If you are here to play a game of magic, and the opponent has good quality proxies, then it shouldn't matter if they are real or not. It shouldn't have any affect on either you or your opponent's enjoyment of the game. Getting beat by a proxy deck is no different than getting beat by a $5000 legacy deck.
Also, for those of us that aren't made of money or have wealthy parents feeding our hobbies (which I am positive is a fairly sizable chunk of the MTG population), proxying is the only logical way of testing a deck out in real life without spending insane amounts of money for cardboard that you may decide you don't even like using.