msem-instigator

As long as you control another creature with flying, Wild Skycub has flying.

Colossal 4—{5}{G} (You may cast this for its colossal cost to have it enter with four +1/+1 counters; or pay {5}{G} as a sorcery: Put four +1/+1 counters on it if it has none.)
Trample

{B}, {T}: Destroy target tapped creature.

{1}, Sacrifice another creature: Wildborn Swindler deals 1 damage to target player or planeswalker. Scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)
{1}, Discard a card at random: Wildborn Swindler deals 1 damage to you. Draw a card.

At the beginning of combat on your turn, if you control a creature with power 4 or greater, put a +1/+1 counter on Wilderkin Zealot.
{R}{G}: Target creature gains trample until end of turn.

Surveil 1, then draw a card. (To surveil 1, look at the top card of your library. You may put that card into your graveyard.)
Create a tapped Treasure token.

{2}{R/G}: Wildershrine Warden gets +2/+2 until end of turn. You may have it assign its combat damage this turn as though it weren't blocked. Activate only once each turn.

Trample
As long as you control an Elemental creature, Wildheart Gorran gets +1/+1.

Flying
{0}: Willowing Wisp becomes the color of your choice until end of turn.

Destroy target artifact or enchantment.
Cycling {2} ({2}, Discard this card: Draw a card.)

{1}{G}, Remove a -1/-1 counter from a creature you control: Wiltthorn Elemental gets +2/+2 until end of turn.

Deathtouch

Whenever you cast a Knight spell or an Adventure spell, Wimbledon's Squire gets +1/+1 until end of turn.

Create a 1/1 green and white Mouse Soldier creature token with vigilance and a 1/1 white and black Badger Cleric creature token with lifelink.

Flying
Whenever Wind Savant attacks, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Wind Savant gets +1/+1 until end of turn.

Counter target spell that targets you or a permanent you control. If that spell targeted a creature, put a +1/+1 counter on that creature.

Flash (You may cast this spell any time you could cast an instant.)
When Wind-Blessed Guardian enters, you may return target permanent you control to its owner's hand.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
When Winding Snake has three or more +1/+1 counters on it, remove them all and transform it.

Flying
When Windwielder enters, you may return target Inscription card from your graveyard to your hand.

Flying
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Wings of Liberty enters with a +1/+1 counter on it.
{1}: Move a +1/+1 counter from Wings of Liberty to equipped creature.
Equipped creature has flying.
Equip {1}

Flying
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
As long as Wings of Trust has three or more +1/+1 counters on it, it has lifelink and vigilance.

Equipped creature gets +1/+1 and has flying and haste.
Equip {3}

Flying
Revive {1}{B}{B} ({1}{B}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Deathtouch
Whenever another creature named Winter's Whelp you control enters, you draw a card and you lose 1 life.