Darksteel Mutation

Enchant creature
Enchanted creature is an Insect artifact creature with base power and toughness 0/1 and has indestructible, and it loses all other abilities, card types, and creature types.

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Scourge of the Nobilis

Enchant creature
As long as enchanted creature is red, it gets +1/+1 and has "{R/W}: This creature gets +1/+0 until end of turn."
As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)

Aspect of Mongoose

Enchant creature
Enchanted creature has shroud. (It can't be the target of spells or abilities.)
When Aspect of Mongoose is put into a graveyard from the battlefield, return Aspect of Mongoose to its owner's hand.

Mantle of the Ancients

Enchant creature you control
When Mantle of the Ancients enters, return any number of target Aura and/or Equipment cards from your graveyard to the battlefield attached to enchanted creature.
Enchanted creature gets +1/+1 for each Aura and Equipment attached to it.

Well Rested

Enchant creature
Enchanted creature has "Whenever this creature becomes untapped, put two +1/+1 counters on it, then you gain 2 life and draw a card. This ability triggers only once each turn."

Aura Gnarlid

Creatures with power less than Aura Gnarlid's power can't block it.
Aura Gnarlid gets +1/+1 for each Aura on the battlefield.

Pacifism

Enchant creature
Enchanted creature can't attack or block.

Pip-Boy 3000

Whenever equipped creature attacks, choose one —
• Sort Inventory — Draw a card, then discard a card.
• Pick a Perk — Put a +1/+1 counter on that creature.
• Check Map — Untap up to two target lands.
Equip {2}

Dogmeat, Ever Loyal

When Dogmeat enters, mill five cards, then return an Aura or Equipment card from your graveyard to your hand.
Whenever a creature you control that's enchanted or equipped attacks, create a Junk token. (It's an artifact with "{T}, Sacrifice this artifact: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.")

Mowu, Loyal Companion

Vigilance, trample
If one or more +1/+1 counters would be put on Mowu, Loyal Companion, that many plus one +1/+1 counters are put on it instead.