Boreal Elemental

Flying
Spells your opponents cast that target Boreal Elemental cost {2} more to cast.

Ashaya, Soul of the Wild

Ashaya, Soul of the Wild's power and toughness are each equal to the number of lands you control.
Nontoken creatures you control are Forest lands in addition to their other types. (They're still affected by summoning sickness.)

Air-Cult Elemental

Flying
Whirlwind — When Air-Cult Elemental enters the battlefield, return up to one other target creature to its owner's hand.

Cavalier of Night

Lifelink
When Cavalier of Night enters the battlefield, you may sacrifice another creature. When you do, destroy target creature an opponent controls.
When Cavalier of Night dies, return target creature card with mana value 3 or less from your graveyard to the battlefield.

Arboretum Elemental

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Have

Muldrotha, the Gravetide

During each of your turns, you may play a land and cast a permanent spell of each permanent type from your graveyard. (If a card has multiple permanent types, choose one as you play it.)

Barkweave Crusher

Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)