Selvala, Heart of the Wilds

Whenever another creature enters, its controller may draw a card if its power is greater than each other creature's power.
{G}, {T}: Add X mana in any combination of colors, where X is the greatest power among creatures you control.

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Return to Action

Until end of turn, target creature gets +1/+0 and gains lifelink and "When this creature dies, return it to the battlefield tapped under its owner's control."

Tend the Pests

As an additional cost to cast this spell, sacrifice a creature.
Create X 1/1 black and green Pest creature tokens with "When this creature dies, you gain 1 life," where X is the sacrificed creature's power.

Freelance Muscle

Whenever Freelance Muscle attacks or blocks, it gets +X/+X until end of turn, where X is the greatest power and/or toughness among other creatures you control.

Unnatural Growth

At the beginning of each combat, double the power and toughness of each creature you control until end of turn.

Curse of the Werefox

Create a Monster Role token attached to target creature you control. When you do, that creature fights up to one target creature you don't control. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has trample. Creatures that fight each deal damage equal to their power to the other.)

Fungal Sprouting

Create X 1/1 green Saproling creature tokens, where X is the greatest power among creatures you control.

Surrak and Goreclaw

Trample
Other creatures you control have trample.
Whenever another nontoken creature you control enters, put a +1/+1 counter on it. It gains haste until end of turn.

Contest of Claws

Target creature you control deals damage equal to its power to another target creature. If excess damage was dealt this way, discover X, where X is that excess damage. (Exile cards from the top of your library until you exile a nonland card with that mana value or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Undying Malice

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Linebreaker Baloth

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.)
Linebreaker Baloth can't be blocked by creatures with power 2 or less.

Demonic Embrace

Enchant creature
Enchanted creature gets +3/+1, has flying, and is a Demon in addition to its other types.
You may cast Demonic Embrace from your graveyard by paying 3 life and discarding a card in addition to paying its other costs.

Traverse the Outlands

Search your library for up to X basic land cards, where X is the greatest power among creatures you control. Put those cards onto the battlefield tapped, then shuffle.

Minion's Return

Flash
Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

Ambitious Dragonborn

Ambitious Dragonborn enters with X +1/+1 counters on it, where X is the greatest power among creatures you control and creature cards in your graveyard.

Goreclaw, Terror of Qal Sisma

Creature spells you cast with power 4 or greater cost {2} less to cast.
Whenever Goreclaw, Terror of Qal Sisma attacks, each creature you control with power 4 or greater gets +1/+1 and gains trample until end of turn.

Demonic Gifts

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield under its owner's control."

Surestrike Trident

Equipped creature has first strike and "{T}, Unattach Surestrike Trident: This creature deals damage equal to its power to target player or planeswalker."
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Tanuki Transplanter

Whenever Tanuki Transplanter or equipped creature attacks, add an amount of {G} equal to its power. Until end of turn, you don't lose this mana as steps and phases end.
Reconfigure {3} ({3}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Undying Evil

Target creature gains undying until end of turn. (When it dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Bessie, the Doctor's Roadster

Haste
Whenever Bessie attacks, another target legendary creature can't be blocked this turn.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Trailblazer's Boots

Equipped creature has nonbasic landwalk. (It can't be blocked as long as defending player controls a nonbasic land.)
Equip {2}

Hunter's Prowess

Until end of turn, target creature gets +3/+3 and gains trample and "Whenever this creature deals combat damage to a player, draw that many cards."

Kaya's Ghostform

Enchant creature or planeswalker you control
When enchanted permanent dies or is put into exile, return that card to the battlefield under your control.

Yargle and Multani

Fake Your Own Death

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control and you create a Treasure token." (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Ruthless Technomancer

When Ruthless Technomancer enters, you may sacrifice another creature you control. If you do, create a number of Treasure tokens equal to that creature's power.
{2}{B}, Sacrifice X artifacts: Return target creature card with power X or less from your graveyard to the battlefield. X can't be 0.

Hexbane Tortoise

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
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.)

Pathbreaker Ibex

Whenever Pathbreaker Ibex attacks, creatures you control gain trample and get +X/+X until end of turn, where X is the greatest power among creatures you control.

Essence Harvest

Target player loses X life and you gain X life, where X is the greatest power among creatures you control.

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Mandate of Abaddon

Choose target creature you control. Destroy all creatures with power less than that creature's power.

Dragon Throne of Tarkir

Equipped creature has defender and "{2}, {T}: Other creatures you control gain trample and get +X/+X until end of turn, where X is this creature's power."
Equip {3}

Overwhelming Stampede

Until end of turn, creatures you control gain trample and get +X/+X, where X is the greatest power among creatures you control.

Not Dead After All

Until end of turn, target creature you control gains "When this creature dies, return it to the battlefield tapped under its owner's control, then create a Wicked Role token attached to it." (Enchanted creature gets +1/+1. When this Aura is put into a graveyard, each opponent loses 1 life.)

Jarad, Golgari Lich Lord

Jarad, Golgari Lich Lord gets +1/+1 for each creature card in your graveyard.
{1}{B}{G}, Sacrifice another creature: Each opponent loses life equal to the sacrificed creature's power.
Sacrifice a Swamp and a Forest: Return Jarad from your graveyard to your hand.

Khalni Territory

Khalni Territory enters tapped.
{T}: Add {G}.

Khalni Ambush

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Khalni Ambush // Khalni Territory

Rite of Consumption

As an additional cost to cast this spell, sacrifice a creature.
Rite of Consumption deals damage equal to the sacrificed creature's power to target player or planeswalker. You gain life equal to the damage dealt this way.

Feign Death

Berserk

Cast this spell only before the combat damage step.
Target creature gains trample and gets +X/+0 until end of turn, where X is its power. At the beginning of the next end step, destroy that creature if it attacked this turn.

Suspicious Bookcase

Defender
{3}, {T}: Target creature can't be blocked this turn.

Spinning Wheel Kick

Target creature you control deals damage equal to its power to each of X target creatures and/or planeswalkers.

Indomitable Might

Flash
Enchant creature
Enchanted creature gets +3/+3.
Enchanted creature's controller may have it assign its combat damage as though it weren't blocked.

Dying Wish

Enchant creature you control
When enchanted creature dies, target player loses X life and you gain X life, where X is its power.

Disciple of Bolas

When Disciple of Bolas enters, sacrifice another creature. You gain X life and draw X cards, where X is that creature's power.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

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.)