Man-o'-War

When Man-o'-War enters, return target creature to its owner's hand.

Ironshell Beetle

When Ironshell Beetle enters, put a +1/+1 counter on target creature.

{1}, Sacrifice a permanent: You gain 1 life.

Flying
When Cloud of Faeries enters, untap up to two lands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
{G}: Regenerate River Boa.

{T}, Exile this artifact: Shuffle your graveyard into your library.

When Ravenous Rats enters, target opponent discards a card.

When Monk Realist enters, destroy target enchantment.

When Elvish Pioneer enters, you may put a basic land card from your hand onto the battlefield tapped.

Whenever you cast a creature spell, you may pay {1}. If you do, return target creature to its owner's hand.

Defender (This creature can't attack.)
Flying
Prevent all combat damage that would be dealt to and dealt by this creature.

Skip your draw step.
Whenever you play a card, draw a card.
Your maximum hand size is two.

Any player may cast creature spells with mana value 3 or less without paying their mana costs and as though they had flash.