Flametongue Kavu

When Flametongue Kavu enters, it deals 4 damage to target creature.

Valor in Akros

Whenever a creature you control enters, creatures you control get +1/+1 until end of turn.

Rix Maadi Reveler

Spectacle {2}{B}{R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
When Rix Maadi Reveler enters, discard a card, then draw a card. If Rix Maadi Reveler's spectacle cost was paid, instead discard your hand, then draw three cards.

Boros Guildgate

Boros Guildgate enters tapped.
{T}: Add {R} or {W}.

Venomous Hierophant

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Venomous Hierophant enters, mill three cards. (Put the top three cards of your library into your graveyard.)

Rakdos Guildgate

Rakdos Guildgate enters tapped.
{T}: Add {B} or {R}.

Alpine Guide

When Alpine Guide enters, you may search your library for a Mountain card, put that card onto the battlefield tapped, then shuffle.
Alpine Guide attacks each combat if able.
When Alpine Guide leaves the battlefield, sacrifice a Mountain.

Gorging Vulture

Flying
When Gorging Vulture enters, mill four cards. You gain 1 life for each creature card milled this way. (To mill four cards, put the top four cards of your library into your graveyard.)

Banisher Priest

When Banisher Priest enters, exile target creature an opponent controls until Banisher Priest leaves the battlefield.

Plains

Noosegraf Mob

Noosegraf Mob enters with five +1/+1 counters on it.
Whenever a player casts a spell, remove a +1/+1 counter from Noosegraf Mob. If you do, create a 2/2 black Zombie creature token.

Urbis Protector

When Urbis Protector enters, create a 4/4 white Angel creature token with flying.

Offspring's Revenge

At the beginning of combat on your turn, exile target red, white, or black creature card from your graveyard. Create a token that's a copy of that card, except it's 1/1. It gains haste until your next turn.

Goremand

As an additional cost to cast this spell, sacrifice a creature.
Flying
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
When Goremand enters, each opponent sacrifices a creature.

Rambunctious Mutt

When Rambunctious Mutt enters, destroy target artifact or enchantment an opponent controls.

Cathartic Reunion

As an additional cost to cast this spell, discard two cards.
Draw three cards.

Mountain

Cataclysmic Gearhulk

Vigilance
When Cataclysmic Gearhulk enters, each player chooses an artifact, a creature, an enchantment, and a planeswalker from among the nonland permanents they control, then sacrifices the rest.

Orzhov Guildgate

Orzhov Guildgate enters tapped.
{T}: Add {W} or {B}.

Swamp

Unburial Rites

Return target creature card from your graveyard to the battlefield.
Flashback {3}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Auramancer

When Auramancer enters, you may return target enchantment card from your graveyard to your hand.