msem-instigator

Motivate 2 (When this creature enters, you may motivate target creature with less power than this by putting two +1/+1 counters on it.)

Ferocious — At the beginning of each combat, if you control a creature with power 4 or greater, Impressible Cub gets +1/+1 until end of turn.

Enchant creature
When Inborn Instincts enters, enchanted creature deals damage equal to its power to target creature an opponent controls.
Enchanted creature gets +6/+6.

Spells and abilities you control that target Inconspicuous Sheep cost {1} less.
As long as Inconspicuous Sheep is enchanted or equipped, they're a 3/3 legendary Sheep Rogue named Agent S.

Create a tapped colorless Powercell artifact token with “{T}: Add {C}.” It doesn't untap during its controller's next untap step.

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{1}: Target creature in Indomitable Anchorite's pack gains indestructible until end of turn. (Two or more creatures you control with equal power are in a pack.)

Creatures you control attacking causes their death knell to trigger.
Death knell — Indomitable Spirit gets +2/+2 and gains trample until end of turn. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

Target creature you control deals damage equal to its power to target creature you don't control.
Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Create two 1/1 green Insect creature tokens, then put a +1/+1 counter on target creature you control for each Insect you control.

Whenever a creature you control with power 4 or greater deals combat damage to a player, you may draw a card.

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.
{8}{G}, Exile Influence of Kruphix from your graveyard: Return up to two target cards from your graveyard to your hand.

When Influential Wildborn enters, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)
Persist (When this creature 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.)

Target creature you control has base power and toughness 5/5 and gains trample until end of turn.

When Ingredient Scroungers enters, if you control a creature with deathtouch, return target permanent card from your graveyard to your hand.

Enchant creature
Enchanted creature gets +2/+0 and has trample.

Whenever a creature you control enters for the second time each turn, it gains haste until end of turn. You may have it get +1/+1 until end of turn.

Whenever Insatiable Abomination or another Horror you control enters, each player mills four cards.
Exile a creature card from your graveyard: Tap target Horror you control. It gains indestructible until end of turn.

Interan Soothsayer gets +1/+1 for each other green creature you control.
{G}, {T}: Put a +1/+1 counter on target green creature.

This spell costs {1} less to cast for each creature type among creatures you control.
Return up to two target cards from your graveyard to your hand. Exile Intersection of Fates.

Whenever you tap a land for mana, add one mana of any type that land produced.
Sacrifice Into Strange Territories: Untap up to two lands.

Choose one or both —
• Create two 1/1 white Soldier creature tokens. They gain haste until end of turn.
• Create an 8/0 green Scorpion creature token with trample.

Search your library for a Forest card, put it onto the battlefield, then shuffle.

When Intrepid Shieldmate enters, target creature gets +1/+1 until end of turn.

Create two 1/1 green Elf creature tokens, then up to one target creature gets +X/+X until end of turn, where X is the number of creatures you control. (Targets are chosen before the tokens are created.)