Card advantage is something that's always appreciated in red, and the Dracosaur draws you an additional two cards every turn while also providing additional creatures and mana
It triggers itself too, so you can attack with it on two, leaving up two mana, at which point your opponent just has to take the hit, and it's likely to grow later in the game too
The simplest form of this combo is to have The Lunar Whale, Senseis Divining Top, and Glaring Fleshraker
Skipping down to the third and fourth most valuable cards at release, we have two more legendary creatures: The Wall of Ba Sing Se ($15) and Koh, the Face Stealer ($7)
With Adventures in the Forgotten Realms arrival, it turns out that MTG now has classes too
Wizards of the Coast, the company behind Magic, did make some changes