Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Atla Palani, Nest Tender

{2}, {T}: Create a 0/1 green Egg creature token with defender.
Whenever an Egg you control dies, reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Samut, Voice of Dissent

Flash
Double strike, vigilance, haste
Other creatures you control have haste.
{W}, {T}: Untap another target creature.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Nesting Dragon

Flying
Landfall — Whenever a land you control enters, create a 0/2 red Dragon Egg creature token with defender and "When this creature dies, create a 2/2 red Dragon creature token with flying and '{R}: This creature gets +1/+0 until end of turn.'"