Paramecia Coloniex

When this creature enters, mill three cards. (Put the top three cards of your library into your graveyard.)
When this creature dies, you may exile it. When you do, put target creature card from your graveyard on top of your library.

Rat King, Verminister

Disappear — At the beginning of your end step, if a permanent left the battlefield under your control this turn, create a 1/1 black Rat creature token and put a +1/+1 counter on Rat King.
{T}, Sacrifice three Rats: Return target creature card and all other cards with the same name as that card from your graveyard to the battlefield tapped.

Savanti Romero, Time's Exile

Trample
At the beginning of combat on your turn, put a +1/+1 counter on Savanti Romero. Then you draw X cards and lose X life, where X is the number of counters on Savanti Romero.

Shark Shredder, Killer Clone

Sneak {3}{B}{B}
First strike
Whenever Shark Shredder deals combat damage to a player, put up to one target creature card from that player's graveyard onto the battlefield under your control. It enters tapped and attacking that player.

Shredder, Unrelenting

Sneak {3}{B} (You may cast this spell for {3}{B} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Deathtouch
Whenever Shredder enters or attacks, another target creature you control gains deathtouch until end of turn.

Shredder's Armor

Equipped creature gets +2/+1.
When this Equipment enters, attach it to target creature you control.
Equip—Sacrifice another nonland permanent. Activate only once each turn.

Shredder's Revenge

Choose one —
• Target player discards two cards.
• Target player draws two cards and loses 2 life.

Shredder's Technique

Sneak {B} (You may cast this spell for {B} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Destroy target creature or enchantment. If an enchantment was destroyed this way, you lose 2 life.

South Wind Avatar

Deathtouch
Whenever another creature you control dies, you gain life equal to its toughness.
Whenever you gain life, each opponent loses 1 life.

Splinter, Hamato Yoshi

Sneak {B} (You may cast this spell for {B} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Menace (This creature can't be blocked except by two or more creatures.)
Other Ninjas you control get +1/+1.

Hamato Guardian Stance

Target creature gets +1/+3 and gains flying until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Splinter's Technique

Sneak {1}{B} (You may cast this spell for {1}{B} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Search your library for a card, put that card into your hand, then shuffle.

Squirrelanoids

Stomped by the Foot

Kicker—Sacrifice an artifact or creature. (You may sacrifice an artifact or creature in addition to any other costs as you cast this spell.)
Target creature gets -2/-2 until end of turn. If this spell was kicked, that creature gets -5/-5 until end of turn instead.

Super Shredder

Menace
Whenever another permanent leaves the battlefield, put a +1/+1 counter on Super Shredder.

Tunnel Rats

{4}{B}: Return this card from your graveyard to the battlefield tapped.

Teenage Mutant Ninja Turtles