7 mana 5/10 with an upside - the stats are optimal (7 mana 7/(7+1)) and it has an snowball effect.
I personally think this is a great card in arena. It's very durable and after a trade or two this can become a nice late-game finisher. But I don't see it in constructed, it's just too slow and not impactful enough. This could potentially be included in a mid-range deck, but we will see.
I mean it passes the vanilla test (15 stats for 7), the overkill gets easier to trigger each time, and it has high health so it's hard to kill. It's got a chance of seeing play, but it is slow and it does do nothing the turn it is played. Druid and Warrior can cheat it out so it could go there. It is excellent with Windfury so maybe Shaman? And paladin can buff it to make it scary faster.
Kind of reminds me of Stasis Drake for some reason. Ideally you want this to become a 10/10 and then you start going face with it but it’s just way too slow and way too easily removable and doesn’t do anything when you play it and has a bunch of other problems. Sick in Arena tho.