Imoti, Celebrant of Bounty

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Spells you cast with mana value 6 or greater have cascade.

Flaming Tyrannosaurus

Menace
Paradox — Whenever you cast a spell from anywhere other than your hand, Flaming Tyrannosaurus deals 3 damage to any target. Then put a +1/+1 counter on Flaming Tyrannosaurus.
When Flaming Tyrannosaurus dies, it deals damage equal to its power to each opponent.

Aurora Phoenix

Flying
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Whenever you cast a spell with cascade, return Aurora Phoenix from your graveyard to your hand.

Etali's Favor

Enchant creature you control
When Etali's Favor enters, discover 3. (Exile cards from the top of your library until you exile a nonland card with mana value 3 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)
Enchanted creature gets +1/+1 and has trample.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Noise Marine

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Sonic Blaster — When Noise Marine enters, it deals damage equal to the number of spells you've cast this turn to any target.

The Lost and the Damned

Whenever a land you control enters from anywhere other than your hand or you cast a spell from anywhere other than your hand, create a 3/3 red Spawn creature token.

Bloodbraid Elf

Haste (This creature can attack and {T} as soon as it comes under your control.)
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Maelstrom Wanderer

Creatures you control have haste.
Cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Then do it again.)

Keeper of Secrets

First strike, haste
Symphony of Pain — Whenever you cast a spell from anywhere other than your hand, Keeper of Secrets deals damage equal to that spell's mana value to target opponent.

Llanowar Elves

Sol Ring

Averna, the Chaos Bloom

As you cascade, you may put a land card from among the exiled cards onto the battlefield tapped. (Do this after the last card is exiled but before deciding whether to cast a nonland card.)

Temur Ascendancy

Creatures you control have haste.
Whenever a creature you control with power 4 or greater enters, you may draw a card.

Birds of Paradise

Garruk's Uprising

When Garruk's Uprising enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample.
Whenever a creature you control with power 4 or greater enters, draw a card.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Etali, Primal Sickness

Trample, indestructible
Whenever Etali, Primal Sickness deals combat damage to a player, they get that many poison counters. (A player with ten or more poison counters loses the game.)

Etali, Primal Conqueror

Trample
When Etali, Primal Conqueror enters, each player exiles cards from the top of their library until they exile a nonland card. You may cast any number of spells from among the nonland cards exiled this way without paying their mana costs.
{9}{G/P}: Transform Etali. Activate only as a sorcery.

Etali, Primal Conqueror // Etali, Primal Sickness

Etali, Primal Storm

Whenever Etali, Primal Storm 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.

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Trumpeting Carnosaur

Trample
When Trumpeting Carnosaur enters, discover 5.
{2}{R}, Discard Trumpeting Carnosaur: It deals 3 damage to target creature or planeswalker.

Heralds of Tzeentch

Flying
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Selvala, Heart of the Wilds

Whenever another creature enters, its controller may draw a card if its power is greater than each other creature's power.
{G}, {T}: Add X mana in any combination of colors, where X is the greatest power among creatures you control.

Apex Devastator

Cascade, cascade, cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Multiple instances of cascade each trigger separately.)