As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle your library.

Flash (You may cast this spell any time you could cast an instant.)
Flying
When Hollowhenge Spirit enters the battlefield, remove target attacking or blocking creature from combat.

When Honey Mammoth enters the battlefield, you gain 4 life.

Create a 2/2 green Wolf creature token for each Forest you control.

Put a +1/+1 counter on target creature you control. Then that creature fights target creature you don't control. (Each deals damage equal to its power to the other.)

Spend only mana produced by basic lands to cast this spell.

Kird Chieftain gets +1/+1 as long as you control a Forest.
: Target creature gets +2/+2 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
As long as you control a legendary Samurai, Konda's Hatamoto gets +1/+2 and has vigilance. (Attacking doesn't cause this creature to tap.)

Trample
Scavenge (, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Haste
When Lathnu Hellion enters the battlefield, you get (two energy counters).
At the beginning of your end step, sacrifice Lathnu Hellion unless you pay .

(: Add .)
Leechridden Swamp enters the battlefield tapped.
, : Each opponent loses 1 life. Activate this ability only if you control two or more black permanents.

Whenever equipped creature attacks, it deals damage equal to its power to the player or planeswalker it's attacking.
Equip

Reach (This creature can block creatures with flying.)

Devour 2 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with twice that many +1/+1 counters on it.)
When Marrow Chomper enters the battlefield, you gain 2 life for each creature it devoured.

Enchant creature
When Melancholy enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of your upkeep, sacrifice Melancholy unless you pay .

Flying
Council's dilemma — When Messenger Jays enters the battlefield, starting with you, each player votes for feather or quill. Put a +1/+1 counter on Messenger Jays for each feather vote and draw a card for each quill vote. For each card drawn this way, discard a card.

Target creature gets +2/+2 until end of turn. If you cast this spell during your main phase, that creature gets +4/+4 until end of turn instead.

Flying
When Mindeye Drake dies, target player mills five cards.