Gyox, Brutal Carnivora

At the beginning of your end step, put an oil counter on up to one target creature.
Whenever a nontoken creature you control with one or more oil counters on it dies, conjure X duplicates of it into exile, where X is the number of oil counters on it. Those duplicates perpetually get +X/+X. Then shuffle those duplicates into your library.

Phyresis Roach

Toxic 1
Whenever Phyresis Roach deals combat damage to a player, Insects you control and Insect cards in your graveyard, hand, and library perpetually gain toxic 1.

Kami of Transmutation

When Kami of Transmutation enters or leaves the battlefield, choose one —
• Each permanent card in your hand perpetually becomes an artifact in addition to its other types.
• Each permanent card in your hand perpetually becomes an enchantment in addition to its other types.

Mephidross Slime

Trample
When Mephidross Slime dies, conjure a card named Mephidross Slime into your graveyard. Perpetually double the power and toughness of Mephidross Slime and that card, then shuffle them into their owner's library.

Phyrexian Scrapyard

{T}: Add {C}.
{1}, {T}, Discard a card: Conjure a card named Phyrexian Scrapyard into your hand.
{2}, {T}, Sacrifice three lands named Phyrexian Scrapyard: Conjure a card named Soul of New Phyrexia onto the battlefield. Activate only as a sorcery.

Suntail Squadron

Conjure a card named Suntail Hawk into your hand. If you have fewer than seven cards in hand, repeat this process.

Skullpiercer Gnat

Flying
Toxic 1
Whenever Skullpiercer Gnat deals combat damage to a player, a random nonland card in that player's hand perpetually gains "When you cast this spell, you get a poison counter."