msem-instigator

Target creature gains double strike until end of turn. Mill a card.

Double strike
When Fencing Tutor enters, create a 0/1 white Soldier creature token with double strike.

[+1]: Until your next turn, whenever up to one target permanent deals damage to another permanent or player, it deals that much damage to itself.
[–X]: When you next cast a noncreature spell with mana value X or less this turn, copy it. You may choose new targets for the copy.
[–2]: Create an X/X blue Spirit creature token, where X is the number of colors of mana you've spent to cast spells this turn.

Menace
When Fenhauler Gang enters, each player mills three cards.
Whenever Fenhauler Gang deals combat damage to a player, return up to one target creature or land card from your graveyard to your hand.

Fennec Fostress gets +1/+0 for each Aura you control.

Once each turn, you may cast a creature you control from the battlefield.
(You can cast its Adventure this way.)

{R/G}: Fento, Nova Crusader gains haste and trample until end of turn.
Whenever Fento, Nova Crusader attacks, you may put a creature card from your hand onto the battlefield tapped and attacking. If you do, sacrifice that creature at the beginning of the next end step.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Equipped creature gets +3/+0.
Whenever a creature you control attacks and isn't blocked, you may pay {4}. If you do, attach Feral Cleaver to that creature.
Equip {3}

Trample
When Feral Devout enters, choose one —
• Put a +1/+1 counter on Feral Devout.
• Create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

{1}{R}{G}: Feral Exemplar gets +2/+2 until end of turn. Activate only once each turn.
Ferocious — Whenever a creature you control with power 4 or greater attacks, that creature gets +X/+X until end of turn, where X is its power.

Wanderlust — Feral Ornithax gets +2/+2 and has trample as long as you control four or more differently named lands.

Colossal 3—{4}{R}{G} (You may cast this for its colossal cost to have it enter with three +1/+1 counters; or pay {4}{R}{G} as a sorcery: Put three +1/+1 counters on it if it has none.)
Each creature you control with a counter on it can't be blocked by more than one creature.

When Feralborn Druid enters, create two 2/2 green Wolf creature tokens.
Feralborn Druid gets +1/+1 for each Wolf you control.

Haste
Menace (This creature can't be blocked except by two or more creatures.)
{4}{R}{R}: Ferocious Desert-Hunter gets +X/+0 until end of turn, where X is its power.

Ferocious Flame deals 2 damage to any target. If you control a creature with power 4 or greater, it deals 4 damage instead.

Target creature you control gets +4/+0 and gains trample until end of turn.

When Ferocity of the Redeemed enters, return up to two target creature cards with mana value 1 or less from your graveyard to the battlefield.
Revive {2}{W}{W} ({2}{W}{W}, 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.)

This spell costs {1} less to cast if it targets an attacking creature.
Target creature gets +2/+0 and gains indestructible until end of turn.

Ferried Stagecoach can't be blocked as long as another creature is attacking.
Whenever Ferried Stagecoach deals combat damage to a player, each player flips a coin. Each opponent that loses the flip discards a card, and each player on your team that wins the flip draws a card.

Deathtouch
Infiltrate (Whenever one or more attacking creatures you control aren't blocked, this creature gets +1/+1 until end of turn.)

Whenever Ferris, the Sapphire Storm or another creature you control enters, each opponent mills X cards, where X is that creature's power.

Destroy target artifact or tapped land.

Harvest (You may tap any number of creatures you control as you cast this spell. If you do, reduce this spell's mana cost by their total power.)
Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. You gain 3 life.