Guardian Scalelord

Backup 1 (When this creature enters the battlefield, put a +1/+1 counter on target creature. If that's another creature, it gains the following abilities until end of turn.)
Flying
Whenever this creature attacks, return target nonland permanent card with mana value X or less from your graveyard to the battlefield, where X is this creature's power.

Captain Lannery Storm

Haste
Whenever Captain Lannery Storm attacks, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Whenever you sacrifice a Treasure, Captain Lannery Storm gets +1/+0 until end of turn.

Expensive Taste

Exile the top two cards of target opponent's library face down. You may look at and play those cards for as long as they remain exiled.

Decadent Dragon

Flying, trample
Whenever Decadent Dragon attacks, create a Treasure token.

Decadent Dragon // Expensive Taste

Mirror-Style Master

Backup 1 (When this creature enters the battlefield, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Whenever this creature attacks, for each attacking modified creature you control, create a tapped and attacking token that's a copy of that creature. Exile those tokens at end of combat. (Equipment, Auras you control, and counters are modifications.)

Duke Ulder Ravengard

At the beginning of combat on your turn, another target creature you control gains haste and myriad until end of turn. (Whenever it attacks, for each opponent other than defending player, you may create a token that's a copy of that creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Tori D'Avenant, Fury Rider

Vigilance, trample
Whenever Tori D'Avenant, Fury Rider attacks, all other attacking creatures you control get +1/+1 until end of turn. Other red attacking creatures you control gain trample until end of turn. Untap each other white attacking creature you control.

Bloodvial Purveyor

Flying, trample
Whenever an opponent casts a spell, that player creates a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
Whenever Bloodvial Purveyor attacks, it gets +1/+0 until end of turn for each Blood token defending player controls.

Alesha, Who Smiles at Death

First strike
Whenever Alesha, Who Smiles at Death attacks, you may pay {W/B}{W/B}. If you do, return target creature card with power 2 or less from your graveyard to the battlefield tapped and attacking.

Andúril, Flame of the West

Equipped creature gets +3/+1.
Whenever equipped creature attacks, create two tapped 1/1 white Spirit creature tokens with flying. If that creature is legendary, instead create two of those tokens that are tapped and attacking.
Equip {2}

Heart-Piercer Bow

Whenever equipped creature attacks, Heart-Piercer Bow deals 1 damage to target creature defending player controls.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Drakuseth, Maw of Flames

Flying
Whenever Drakuseth, Maw of Flames attacks, it deals 4 damage to any target and 3 damage to each of up to two other targets.

Pugnacious Pugilist

Whenever Pugnacious Pugilist attacks, create a tapped and attacking 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."
Blitz {3}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Raid Bombardment

Whenever a creature you control with power 2 or less attacks, Raid Bombardment deals 1 damage to the player or planeswalker that creature is attacking.

Adriana, Captain of the Guard

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Other creatures you control have melee. (If a creature has multiple instances of melee, each triggers separately.)

Ash, Party Crasher

Haste
Celebration — Whenever Ash, Party Crasher attacks, if two or more nonland permanents entered the battlefield under your control this turn, put a +1/+1 counter on Ash.

Flamerush Rider

Whenever Flamerush Rider attacks, create a token that's a copy of another target attacking creature and that's tapped and attacking. Exile the token at end of combat.
Dash {2}{R}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

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.

Djeru and Hazoret

As long as you have one or fewer cards in hand, Djeru and Hazoret has vigilance and haste.
Whenever Djeru and Hazoret attacks, look at the top six cards of your library. You may exile a legendary creature card from among them. Put the rest on the bottom of your library in a random order. Until end of turn, you may cast the exiled card without paying its mana cost.

Isshin, Two Heavens as One

If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Shadowfax, Lord of Horses

Horses you control have haste. (They can attack and {T} as soon as they come under your control.)
Whenever Shadowfax, Lord of Horses attacks, you may put a creature card with lesser power from your hand onto the battlefield tapped and attacking.

Greatsword of Tyr

Whenever equipped creature attacks, put a +1/+1 counter on it and tap up to one target creature defending player controls.
Equip {W} ({W}: Attach to target creature you control. Equip only as a sorcery.)

Shagrat, Loot Bearer

Whenever Shagrat, Loot Bearer attacks, attach up to one target Equipment to it. Then amass Orcs X, where X is the number of Equipment attached to Shagrat. (Control of the Equipment doesn't change. To amass Orcs X, put X +1/+1 counters on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)

Ulamog's Crusher

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents.)
Ulamog's Crusher attacks each combat if able.

Shared Animosity

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Éomer of the Riddermark

Haste
Whenever Éomer of the Riddermark attacks, if you control a creature with the greatest power among creatures on the battlefield, create a 1/1 white Human Soldier creature token.

Krenko, Tin Street Kingpin

Whenever Krenko, Tin Street Kingpin attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.