Rocco, Cabaretti Caterer

When Rocco enters, if you cast it, you may search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

Fyndhorn Elves

Decoction Module

Whenever a creature you control enters, you get {E} (an energy counter).
{4}, {T}: Return target creature you control to its owner's hand.

Llanowar Elves

Light the Way

Choose one —
• Put a +1/+1 counter on target creature or Vehicle. Untap it.
• Return target permanent you control to its owner's hand.

First Responder

Vigilance
At the beginning of your end step, you may return another creature you control to its owner's hand, then put a number of +1/+1 counters equal to that creature's power on this creature.

Usher to Safety

Return target permanent you control to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Shepherd of the Flock

Shepherd of the Flock // Usher to Safety

Temur Sabertooth

{1}{G}: You may return another creature you control to its owner's hand. If you do, this creature gains indestructible until end of turn.

Barbarian Guides

{2}{R}, {T}: Choose a land type. Target creature you control gains snow landwalk of the chosen type until end of turn. Return that creature to its owner's hand at the beginning of the next end step. (It can't be blocked as long as defending player controls a snow land of that type.)

Gandalf the White

Flash
You may cast legendary spells and artifact spells as though they had flash.
If a legendary permanent or an artifact entering or leaving the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Wirewood Symbiote

Return an Elf you control to its owner's hand: Untap target creature. Activate only once each turn.

Priest of Titania

{T}: Add {G} for each Elf on the battlefield.

Drannith Magistrate

Your opponents can't cast spells from anywhere other than their hands.

Roaring Primadox

At the beginning of your upkeep, return a creature you control to its owner's hand.

Snow Hound

{1}, {T}: Return this creature and target green or blue creature you control to their owner's hand.

Mistbreath Elder

At the beginning of your upkeep, return another creature you control to its owner's hand. If you do, put a +1/+1 counter on this creature. Otherwise, you may return this creature to its owner's hand.

Cloudstone Curio

Whenever a nonartifact permanent you control enters, you may return another permanent you control that shares a permanent type with it to its owner's hand.

Essence Reliquary

{T}: Return another target permanent you control and all Auras you control attached to it to their owner's hand. Activate only during your turn.

Knotvine Mystic

Archangel of Tithes

Flying
As long as this creature is untapped, creatures can't attack you or planeswalkers you control unless their controller pays {1} for each of those creatures.
As long as this creature is attacking, creatures can't block unless their controller pays {1} for each of those creatures.

Annie Joins Up

When Annie Joins Up enters, it deals 5 damage to target creature or planeswalker an opponent controls.
If a triggered ability of a legendary creature you control triggers, that ability triggers an additional time.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.