One of the Pack

Creature - Werewolf

(Color indicator: One of the Pack is green)

At the beginning of each upkeep, if a player cast two or more spells last turn, transform this creature.

When the howl beckons, he cannot resist the urge to join the others.

5/6

Card has other part: Solitary Hunter

2016-04-08 The abilities that transform a Werewolf back and forth look at the entire previous turn, even if the Werewolf with that ability wasn't on the battlefield for some or all of that turn.
2016-04-08 To trigger the Werewolf's back face's transform ability, a single player must have cast two or more spells during the previous turn. If multiple players each cast just one spell during the previous turn, the ability won't trigger.

Card is in preconstructed decks:

mtg.wtf