Accomplished Automaton

Fabricate 1 (When this creature enters, put a +1/+1 counter on it or create a 1/1 colorless Servo artifact creature token.)

Avalanche Riders

Haste
Echo {3}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Avalanche Riders enters, destroy target land.

Akoum Boulderfoot

When Akoum Boulderfoot enters, it deals 1 damage to any target.

Adaptive Automaton

As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Ancestral Statue

When Ancestral Statue enters, return a nonland permanent you control to its owner's hand.

Anarchist

When Anarchist enters, you may return target sorcery card from your graveyard to your hand.

Aether Chaser

First strike
When Aether Chaser enters, you get {E}{E} (two energy counters).
Whenever Aether Chaser attacks, you may pay {E}{E}. If you do, create a 1/1 colorless Servo artifact creature token.

Akki Rockspeaker

Aethertorch Renegade

When Aethertorch Renegade enters, you get {E}{E}{E}{E} (four energy counters).
{T}, Pay {E}{E}: Aethertorch Renegade deals 1 damage to target creature.
{T}, Pay eight {E}: Aethertorch Renegade deals 6 damage to target player or planeswalker.

Delina, Wild Mage

Whenever Delina, Wild Mage attacks, choose target creature you control, then roll a d20.
1—14 | Create a tapped and attacking token that's a copy of that creature, except it's not legendary and it has "At end of combat, exile this creature."
15—20 | Create one of those tokens. You may roll again.