Vivien, Verdant Warrior

+1: Create two 1/1 wolf elemental creature tokens.
0: Until end of turn, Vivien, Verdant Warrior becomes a legendary 4/3 green human warrior creature with vigilance, hexproof and indestructible.
-X: Sacrifice X 1/1 wolf elemental creature tokens, create that many 5/5 elemental bear creature tokens with haste, trample and vigilance.