Cavern Crawler

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)
{R}: Cavern Crawler gets +1/-1 until end of turn.

Barbed Shocker

Trample, haste
Whenever Barbed Shocker deals damage to a player, that player discards all the cards in their hand, then draws that many cards.

Acridian

Echo {1}{G} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)

Imperial Moth

Befriending the Moths

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Target creature you control gets +1/+1 and gains flying until end of turn.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Befriending the Moths // Imperial Moth

Brain Maggot

When Brain Maggot enters, target opponent reveals their hand and you choose a nonland card from it. Exile that card until Brain Maggot leaves the battlefield.

Beetleform Mage

{G}{U}: Beetleform Mage gets +2/+2 and gains flying until end of turn. Activate only once each turn.

Perfected Form

Aberrant Researcher

Flying
At the beginning of your upkeep, mill a card. If an instant or sorcery card was milled this way, transform Aberrant Researcher.

Aberrant Researcher // Perfected Form

Carrion Beetles

{2}{B}, {T}: Exile up to three target cards from a single graveyard.

Adaptive Shimmerer

Flash
Adaptive Shimmerer enters with three +1/+1 counters on it.

Blister Beetle

When Blister Beetle enters, target creature gets -1/-1 until end of turn.

Caustic Crawler

Landfall — Whenever a land you control enters, you may have target creature get -1/-1 until end of turn.

Caustic Caterpillar

{1}{G}, Sacrifice Caustic Caterpillar: Destroy target artifact or enchantment.

Carrion Ants

{1}: Carrion Ants gets +1/+1 until end of turn.

Broodhatch Nantuko

Whenever Broodhatch Nantuko is dealt damage, you may create that many 1/1 green Insect creature tokens.
Morph {2}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Bayou Dragonfly

Flying; swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Blightbeetle

Protection from green (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything green.)
Creatures your opponents control can't have +1/+1 counters put on them.