msem-instigator

Return up to two target artifact, creature, and/or enchantment cards with mana value 3 or less from your graveyard to the battlefield.
Flashback {4}{W}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

{1}{G}: Until your next turn, Bessie becomes a 5/5 green Wurm creature with trample, haste, and indestructible. You can't activate this ability while Bessie is being attacked. (She doesn't lose loyalty while she's not a planeswalker.)
[+1]: Creatures you control get +1/+1 and gain haste until your next turn.
[–6]: Create five 3/3 green Wurm creature tokens with trample and haste.

When Bessie's Brood enters, it fights target creature. (If there are no other creatures, it eats itself.)

Trample
Bessie's Crusher has haste as long as you control another Wurm.

[+2]: Create a 3/3 red Wurm creature token.
[–2]: Up to three target creatures each get +2/+2 until end of turn. Bessie deals 2 damage to each of up to three target creatures.
[–9]: You get an emblem with “Creatures you control have base power and toughness 7/7 and have indestructible.”

Bestial Mob's power and toughness are each equal to the number of creatures you control.
Whenever Bestial Mob deals combat damage to a player, destroy target creature with toughness less than Bestial Mob's power.

Create a 3/3 green Beast creature token, then populate. (Create a token that's a copy of a creature token you control.)

You may have Better Half enter as a copy of any creature on the battlefield, except it's a Reflection in addition to its other creature types and it has distorted. (It can be blocked by tapped creatures but not untapped creatures.)

Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.

Exile target nonland permanent. Its controller gains 5 life.

Search your library for a land card, put it onto the battlefield tapped, then shuffle.
Coalesce {5}{G}{G} (You may cast this from your graveyard for {5}{G}{G}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Beyond All Horizons's power and toughness are each equal to the number of lands you
control.

Return all creature and planeswalker cards from your graveyard to the battlefield.

Creatures you control get +1/+1 until end of turn.
Artifact creatures and Elementals you control get +1/+1 until end of turn.

When Beyond the Boneyard enters, exile another target nonland permanent until Beyond the Boneyard leaves the battlefield.
Your opponents can't cast spells that share a card type with the exiled card during postcombat main phases.

Create two tapped colorless land tokens named Far-Off Lands with “{T}: Add one mana of any color.” (Then exile this card. You may cast the creature later from exile.)

Look at the top ten cards of your library. Put any number of legendary permanents with total mana value 6 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.
For each planeswalker you control, you may activate one of their loyalty abilities. (You still pay its costs.)

Enchant creature
Converge — When Big Enough enters, put X +1/+1 counters on enchanted creature, where X is number of colors of mana spent to cast Big Enough.
Enchanted creature has trample.

When Big Rock enters, it deals 2 damage to any target.
{T}: Add {C}.
{T}, Sacrifice Big Rock: It deals 2 damage to any target. Activate this ability only if you control a Giant.

Pressure {2}{G} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card with mana value X or less, where X is equal to twice the sacrificed creature's mana value, put it onto the battlefield, then shuffle.

Menagerie — This spell costs {2} less to cast if there are five or more creature types among creatures you control.
Destroy target creature with power or toughness 4 or greater.

Trample, haste, indestructible
Whenever a permanent an opponent controls is put into a graveyard from the battlefield, put a +1/+1 counter on target Ooze.

Enchant creature
Enchanted creature gets +2/+2 and has lifelink.

When Biohazard enters, destroy all other nonland permanents with mana value X or less.
At the beginning of each end step, each opponent loses life equal to the number of cards they've drawn this turn plus the number of spells they've cast this turn.

Return up to one target spell to its owner's hand.
Create two 1/1 blue Elemental creature tokens with flying. They can't block this turn.

When Bird Call enters, search your library for a creature card, reveal it, shuffle, then put that card on top.
{2}, {T}: Target creature gets +1/+1 until end of turn.