Metamorphosis

As an additional cost to cast this spell, sacrifice a creature.
Add X mana of any one color, where X is 1 plus the sacrificed creature's mana value. Spend this mana only to cast creature spells.

Barbary Apes

Thorn Elemental

You may have this creature assign its combat damage as though it weren't blocked.

Compost

Whenever a black card is put into an opponent's graveyard from anywhere, you may draw a card.

Emerald Dragonfly

Flying
{G}{G}: This creature gains first strike until end of turn.

Pattern of Rebirth

Enchant creature
When enchanted creature dies, that creature's controller may search their library for a creature card, put that card onto the battlefield, then shuffle.

Rust

Counter target activated ability from an artifact source. (Mana abilities can't be targeted.)

Momentum

Enchant creature
At the beginning of your upkeep, you may put a growth counter on this Aura.
Enchanted creature gets +1/+1 for each growth counter on this Aura.