Knuckles the Echidna

Double strike, trample, haste
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token.
Treasure Hunter — At the beginning of your upkeep, if you control thirty or more artifacts, you win the game.

Rankle, Master of Pranks

Flying, haste
Whenever Rankle deals combat damage to a player, choose any number —
• Each player discards a card.
• Each player loses 1 life and draws a card.
• Each player sacrifices a creature of their choice.

Nether Shadow

Haste
At the beginning of your upkeep, if this card is in your graveyard with three or more creature cards above it, you may put this card onto the battlefield.

Goldspan Dragon

Flying, haste
Whenever this creature attacks or becomes the target of a spell, create a Treasure token.
Treasures you control have "{T}, Sacrifice this artifact: Add two mana of any one color."

Bloodghast

This creature can't block.
This creature has haste as long as an opponent has 10 or less life.
Landfall — Whenever a land you control enters, you may return this card from your graveyard to the battlefield.

Shadow the Hedgehog

Haste
Whenever Shadow the Hedgehog or another creature you control with flash or haste dies, draw a card.
Chaos Control — Each spell you cast has split second if mana from an artifact was spent to cast it. (As long as it's on the stack, players can't cast spells or activate abilities that aren't mana abilities.)

Mirri the Cursed

Flying, first strike, haste
Whenever Mirri deals combat damage to a creature, put a +1/+1 counter on Mirri.

Nether Traitor

Haste
Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever another creature is put into your graveyard from the battlefield, you may pay {B}. If you do, return this card from your graveyard to the battlefield.

Sokenzan, Crucible of Defiance

{T}: Add {R}.
Channel — {3}{R}, Discard this card: Create two 1/1 colorless Spirit creature tokens. They gain haste until end of turn. This ability costs {1} less to activate for each legendary creature you control.

Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni.
Sacrifice another creature: Yahenni gains indestructible until end of turn.

Ichorid

Haste
At the beginning of the end step, sacrifice this creature.
At the beginning of your upkeep, if this card is in your graveyard, you may exile a black creature card other than this card from your graveyard. If you do, return this card to the battlefield.

Clackbridge Troll

Trample, haste
When this creature enters, target opponent creates three 0/1 white Goat creature tokens.
At the beginning of combat on your turn, any opponent may sacrifice a creature of their choice. If a player does, tap this creature, you gain 3 life, and you draw a card.