In Hearthstone there are certain cards which don't work in a regular game but which work perfectly well in Arena! Obviously there are a lot that work for both, but this game mode has some particular features that leave place to other creatures. It is often more difficult to manage the big creatures in Arena and you absolutely must have a good presence on the board at the risk of not being able to come back otherwise.
The basic stats are decent, but in this case it's the ability which justifies the place of this card in this list. In turn 4 there will be almost no creature to overcome your taunt. If you don't have the chance to play it then, it will still be useful for buying some time in the game and letting you breathe. So this card has a double effect, either to show your superiority on the board, or to get back into the game.
Like the Yeti, the stats of the Ogre are very good with a 6/7 for six mana. This card ensures you a good late game and could be a real pain for your opponent. You shouldn't overlook the part played by a "big" card in Arena because it will be much more difficult to manage in a regular game.
This card has a very high mana cost but has a huge advantage with an ability effective immediately when it is placed on the board. The risk is obviously having this card early in the game, because it requires you to have at least on creature on the table to be effective. If you play this creature at the right moment it can allow you to simply take your opponent by the throat and ensure your victory.
A 3/2 card for two mana is already good! It allows you to trade easily in the early game and take you place on the board. Its ability is of considerable use because it allows you to rid yourself of your opponent's weapon, so you get the most from the card. Depending on your opponent's class, it can be useful to keep it to counter your enemy. The weapons of classes like the Paladin or the Warrior are used a lot in Arena, and the ooze will be the ideal counter. So this card is good if played generally, and excellent if its ability is used.
This is a typical example of a card without much use in a regular deck, but which comes into its own in Arena. Managing big creatures can often be a problem in Arena because nothing guarantees that you have drafted what you need. Also, this card quickly arrives on the table and most of the time can't be ignored because of its high damage. This is compensated by the devastating effect of the card when placed on the table!
Board control is essential in Arena, much more than in a regular game. So the cards that allow you to boost minions are very useful, especially for getting rid of an enemy card. This card will allow you to get out of certain situations thanks to its immediate effect and the fact that you're playing a card with decent stats.
This is one of the best turn 5's in the game! The impact of the card is much greater in Arena because you will have two creatures on the board to trade with enemy monsters. You can consider this card as a 6/6 for 5 mana, which simply has no equivalent in the game. The lack of area spells in Arena makes this card a more than judicious choice for keeping or taking control of the board.
This card is very good in all game modes, but even better in Arena! It's a total pain for your opponent. It will often take more than one creature to destroy it due to its deathrattle, making it almost certainly worthwhile. Even if it is ignored, you'll be winning because you can get rid of the little creatures for a low price. In other words, you'll be winning in all situations with a card that can face any test!
There's nothing to say about the basic stats of this card with a 4/4 for 4 mana. It's obviously its ability that makes it interesting with the possibility to give +2 attack to a creature for a turn. Despite the nerf of this card that means this bonus is no longer permanent, the card is still a must have in Arena. It allows you to get rid of a big enemy creature or deal more damage to the hero. This card is very useful for keeping control of the board and neutralising your enemies plans.
The stats of this card speak for themselves! A 4/5 for four mana makes the Yéti one of the best cards you can play on the board in the midgame. If it is played in turn 4, your opponent will be forced to find a way of dealing with it because it is much too big a threat to be ignored.