Bottle Gnomes

Sacrifice Bottle Gnomes: You gain 3 life.

Raven Familiar

Flying
Echo {2}{U} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Raven Familiar enters, look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Island

Manakin

Mask of the Mimic

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card with the same name as target nontoken creature, put that card onto the battlefield, then shuffle.

Triskelion

Triskelion enters with three +1/+1 counters on it.
Remove a +1/+1 counter from Triskelion: It deals 1 damage to any target.

Spike Weaver

Spike Weaver enters with three +1/+1 counters on it.
{2}, Remove a +1/+1 counter from Spike Weaver: Put a +1/+1 counter on target creature.
{1}, Remove a +1/+1 counter from Spike Weaver: Prevent all combat damage that would be dealt this turn.

Mana Leak

Counter target spell unless its controller pays {3}.

Forest

Lifeline

Whenever a creature dies, if another creature is on the battlefield, return the first card to the battlefield under its owner's control at the beginning of the next end step.

Thopter Squadron

Flying
Thopter Squadron enters with three +1/+1 counters on it.
{1}, Remove a +1/+1 counter from Thopter Squadron: Create a 1/1 colorless Thopter artifact creature token with flying. Activate only as a sorcery.
{1}, Sacrifice another Thopter: Put a +1/+1 counter on Thopter Squadron. Activate only as a sorcery.

Wall of Blossoms

Defender
When Wall of Blossoms enters, draw a card.

Llanowar Elves

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Spore Frog

Sacrifice Spore Frog: Prevent all combat damage that would be dealt this turn.

Tinker

As an additional cost to cast this spell, sacrifice an artifact.
Search your library for an artifact card, put that card onto the battlefield, then shuffle.