The only thing stopping me giving this an 8/10 rating is that the kinds of decks that most want walkers that make two dorks and scale up with them dying typically want low curves
Its ability is as follows: as long as Anger is in your graveyard and you control a Mountain, creatures you control have haste
Its not essential to memorise the whole turn structure to play your first games, especially if you have more experienced opponents or mentors around to keep track of things
A hasty Grizzly Bears provides fine pressure, but the combination of pressure and card draw is great: Card draw gives you resources to keep applying the pressure started by your hasty creature
Certainly viable in mono color and colorless decks, at any rate
You could consider taking out the other creature pump card, Great Oak Guardian, though it has flash, so you can use it defensively