Obelisk of Urd isn't really exciting when it hits only one creature, but +2/+2 is a sizable bonus, and even a few creatures receiving the bonus is enough for it to matter
Graveyard decks have always been a huge part of Magic , ever since the first Animate Dead was used to cheat out the first Lord of the Pit or Shivan Dragon
Jacob transforms into Hauken's Insight, a legendary enchantment
On cards that don't get a security stamp (usually commons and uncommons), the acorn will be a printed stamp where the security stamp would have been
You can pay X, one red, and one green, to grant a Wolf or Werewolf you control +x/+0 and trample until the end of the turn
The good news is that most green decks in most constructed formats play Boseiju, which means if you have been playing other formats you likely have these, or if you want to branch out at some point Boseiju will be useful in other places