Arcbound Mouser

Lifelink
Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Westfold Rider

Sacrifice Westfold Rider: Destroy target artifact or enchantment. Activate only as a sorcery.

Searchlight Companion

Flying
When Searchlight Companion enters, create a 1/1 colorless Spirit creature token.

Ceremonial Knife

Equipped creature gets +1/+0 and has "Whenever this creature deals combat damage, create a Blood token." (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Parish-Blade Trainee

Training (Whenever this creature attacks with another creature with greater power, put a +1/+1 counter on this creature.)
When Parish-Blade Trainee dies, put its counters on target creature you control.

Court Homunculus

Court Homunculus gets +1/+1 as long as you control another artifact.

Sanitation Automaton

When Sanitation Automaton enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Skyscanner

Flying
When Skyscanner enters, draw a card.

Unruly Mob

Whenever another creature you control dies, put a +1/+1 counter on Unruly Mob.

Arcbound Prototype

Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Myr Scrapling

Sacrifice Myr Scrapling: Put a +1/+1 counter on target creature.

Salvage Scout

{W}, Sacrifice Salvage Scout: Return target artifact card from your graveyard to your hand.

Foundry Inspector

Artifact spells you cast cost {1} less to cast.

Iron Apprentice

Iron Apprentice enters with a +1/+1 counter on it.
When Iron Apprentice dies, if it had counters on it, put those counters on target creature you control.

Runed Servitor

When Runed Servitor dies, each player draws a card.

Rising Populace

Whenever another creature or planeswalker you control dies, put a +1/+1 counter on Rising Populace.

Myr Sire

When Myr Sire dies, create a 1/1 colorless Phyrexian Myr artifact creature token.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Lembas

When Lembas enters, scry 1, then draw a card.
{2}, {T}, Sacrifice Lembas: You gain 3 life.
When Lembas is put into a graveyard from the battlefield, its owner shuffles it into their library.

Jalum Tome

{2}, {T}: Draw a card, then discard a card.

Glorifier of Suffering

When Glorifier of Suffering enters, you may sacrifice another creature or artifact. When you do, put a +1/+1 counter on each of up to two target creatures.

Ornithopter

Arcane Signet

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

Kami of False Hope

Sacrifice Kami of False Hope: Prevent all combat damage that would be dealt this turn.

Airlift Chaplain

Flying
When Airlift Chaplain enters, mill three cards. You may put a Plains card or a creature card with mana value 3 or less from among the cards milled this way into your hand. If you don't, put a +1/+1 counter on Airlift Chaplain. (To mill a card, put the top card of your library into your graveyard.)

Plains

Workshop Assistant

When Workshop Assistant dies, return another target artifact card from your graveyard to your hand.

Arcbound Stinger

Flying
Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Pilgrim's Eye

Flying
When Pilgrim's Eye enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Armillary Sphere

{2}, {T}, Sacrifice Armillary Sphere: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Voltaic Servant

At the beginning of your end step, untap target artifact.

Miner's Guidewing

Flying, vigilance
When Miner's Guidewing dies, target creature you control explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard.)

Children of Korlis

Sacrifice Children of Korlis: You gain life equal to the life you've lost this turn. (Damage causes loss of life.)

Marble Diamond

Marble Diamond enters tapped.
{T}: Add {W}.

Arcbound Worker

Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Gingerbrute

Haste
{1}: Gingerbrute can't be blocked this turn except by creatures with haste.
{2}, {T}, Sacrifice Gingerbrute: You gain 3 life.

Fodder Tosser

{T}, Discard a card: Fodder Tosser deals 2 damage to target player or planeswalker.

Spirited Companion

When Spirited Companion enters, draw a card.

Filigree Familiar

When Filigree Familiar enters, you gain 2 life.
When Filigree Familiar dies, draw a card.

Auriok Replica

{W}, Sacrifice Auriok Replica: Prevent all damage a source of your choice would deal to you this turn.

Sisay's Ring

Outlaw Medic

Lifelink
When Outlaw Medic dies, draw a card.

Automated Artificer

{T}: Add {C}. Spend this mana only to activate an ability or cast an artifact spell.

Sterling Hound

When Sterling Hound enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Buried Treasure

{T}, Sacrifice Buried Treasure: Add one mana of any color.
{5}, Exile Buried Treasure from your graveyard: Discover 5. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 5 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.)

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Cathar Commando

Flash
{1}, Sacrifice Cathar Commando: Destroy target artifact or enchantment.

Gold Myr

Ecologist's Terrarium

When Ecologist's Terrarium enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{2}, {T}, Sacrifice Ecologist's Terrarium: Put a +1/+1 counter on target creature. Activate only as a sorcery.

Priest of Ancient Lore

When Priest of Ancient Lore enters, you gain 1 life and draw a card.

Tormod's Cryptkeeper

Vigilance
{T}, Sacrifice Tormod's Cryptkeeper: Exile target player's graveyard.

Steadfast Sentry

Vigilance (Attacking doesn't cause this creature to tap.)
When Steadfast Sentry dies, put a +1/+1 counter on target creature you control.

Teshar, Ancestor's Apostle

Flying
Whenever you cast a historic spell, return target creature card with mana value 3 or less from your graveyard to the battlefield. (Artifacts, legendaries, and Sagas are historic.)

Protective Parents

When Protective Parents dies, create a Young Hero Role token attached to up to one target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature has "Whenever this creature attacks, if its toughness is 3 or less, put a +1/+1 counter on it.")

Inspiring Overseer

Flying
When Inspiring Overseer enters, you gain 1 life and draw a card.

Desperate Sentry

When Desperate Sentry dies, create a 3/2 colorless Eldrazi Horror creature token.
Delirium — Desperate Sentry gets +3/+0 as long as there are four or more card types among cards in your graveyard.

Star Pupil

Star Pupil enters with a +1/+1 counter on it.
When Star Pupil dies, put its counters on target creature you control.