Giant Oyster

You may choose not to untap Giant Oyster during your untap step.
{T}: For as long as Giant Oyster remains tapped, target tapped creature doesn't untap during its controller's untap step, and at the beginning of each of your draw steps, put a -1/-1 counter on that creature. When Giant Oyster leaves the battlefield or becomes untapped, remove all -1/-1 counters from the creature.

Vanguard Suppressor

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters the battlefield, create that many tokens that are copies of it.)
Flying
Suppressing Fire — Whenever Vanguard Suppressor deals combat damage to a player, draw a card.

Volo, Guide to Monsters

Whenever you cast a creature spell that doesn't share a creature type with a creature you control or a creature card in your graveyard, copy that spell. (A copy of a creature spell becomes a token.)

Joven's Ferrets

Whenever Joven's Ferrets attacks, it gets +0/+2 until end of turn.
At end of combat, tap all creatures that blocked Joven's Ferrets this turn. They don't untap during their controller's next untap step.

Wonder

Flying
As long as Wonder is in your graveyard and you control an Island, creatures you control have flying.

Volo, Itinerant Scholar

When Volo enters the battlefield, create Volo's Journal, a legendary colorless artifact token with hexproof and "Whenever you cast a creature spell, note one of its creature types that hasn't been noted for this artifact."
{2}, {T}: Draw a card for each creature type noted for target permanent you control named Volo's Journal.
Choose a Background