Hearthpwn

Moonfang and Winged Guardian incoming.

Interesting card, but I don't see it as the new OP. Could be fun to play though. :)

I think this tauren on the card, will be the legendary mercenary for druid. And this is true for priest as well, that the rank spell shows the legendary mercenary. 

 Druid version of Insight, you say? Well, let's look at our beast options in Standard.

Great art, but what does a beast have to do with seeds?

The flavor of cards is getting further and further away from making sense.

Trees attract herbivores? Eh, it's all I got.

The seed is bait for the beast. The longer it grows, the stronger the bait. 

If you take a look at the Rank 2 and Rank 3 versions of this card the flavor is that, by planting the tree, Guff Runetotem was able to catch the attention of small beasts and then bigger and better ones, which aligns with the mana discount part.