Rimefur Reindeer

Whenever an enchantment you control enters, tap target creature an opponent controls.

Stalwart Valkyrie

You may pay {1}{W} and exile a creature card from your graveyard rather than pay this spell's mana cost.
Flying

Harvestguard Alseids

Constellation — Whenever Harvestguard Alseids or another enchantment you control enters, prevent all damage that would be dealt to target creature this turn.

Cooped Up

Enchant creature
Enchanted creature can't attack or block.
{2}{W}: Exile enchanted creature.

Boon of Safety

Put a shield counter on target creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Scry 1.

Due Diligence

Enchant creature
When Due Diligence enters, target creature you control other than enchanted creature gets +2/+2 and gains vigilance until end of turn.
Enchanted creature gets +2/+2 and has vigilance.

Healer's Hawk

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Heliod's Pilgrim

When Heliod's Pilgrim enters, you may search your library for an Aura card, reveal it, put it into your hand, then shuffle.

Spirited Companion

When Spirited Companion enters, draw a card.

Kill Shot

Concordia Pegasus

Tasseled Dromedary

Territorial Hammerskull

Whenever Territorial Hammerskull attacks, tap target creature an opponent controls.

Plains

Petrify

Enchant artifact or creature
Enchanted permanent can't attack or block, and its activated abilities can't be activated.