Cuboid Colony

Flash
Flying, trample
Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)

Quandrix Charm

Choose one —
• Counter target spell unless its controller pays {2}.
• Destroy target enchantment.
• Target creature has base power and toughness 5/5 until end of turn.

Island

Pensive Professor

Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
Whenever one or more +1/+1 counters are put on this creature, draw a card.

Tester of the Tangential

Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
At the beginning of combat on your turn, you may pay {X}. When you do, move X +1/+1 counters from this creature onto another target creature.

Textbook Tabulator

Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
When this creature enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Forest

Wildgrowth Archaic

Trample, reach
Converge — This creature enters with a +1/+1 counter on it for each color of mana spent to cast it.
Whenever you cast a creature spell, that creature enters with X additional +1/+1 counters on it, where X is the number of colors of mana spent to cast it.

Treeguard Duo

When this creature enters, until end of turn, target creature you control gains vigilance and gets +X/+X, where X is the number of creatures you control.

Llanowar Elves

Mind into Matter

Draw X cards. Then you may put a permanent card with mana value X or less from your hand onto the battlefield tapped.

Wild Hypothesis

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it.
Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)