This is a Desu. A rather aggro tribal creature type, all of which are red and green for obvious reasons.

When it comes to strength in numbers and taking advantage of it, Desu seriously outnumber and outgun the notorious Elves. The downside is that the Desu are extremely Desu-centered; the boosts provided by the number of Desu is more or less unacquirable by anything non-Desu. Furthermore, the required balance of red and green mana production can be limiting (although there is one card (so far) which erases that requirement late-term, and a land card which helps evening it out).

The idea of Desu being a force of numbers, of course, originates from Desu spam.

This here is Raging Desu. It's comparable to Heedless One, an uncommon Onslaught 3G Elf with the same abilities (but for Elves rather than Desu). This one has a very restrictive mana cost and is rare. Then again, at the time Heedless One is an 8/8, Raging Desu will probably be a 24/24.