Clever Combo

Search your library for a host card or a card with augment, reveal it, put it into your hand, then shuffle.

Serpentine

Landfall — Whenever a land you control enters,
Augment {2}{G} ({2}{G}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Really Epic Punch

Target creature you control gets +2/+2 if it's a host or has augment. Then it fights target creature you don't control.

Proper Laboratory Attire

Equipped creature gets +2/+1 and has protection from die rolls. (Nothing that lets a player roll a die can block, target, deal damage to, or attach to equipped creature.)
Equip {2}

Shellephant

{0}: Choose one. You may activate this ability while Shellephant is in any zone.
• Shellephant has base power and toughness 1/4.
• Shellephant has base power and toughness 3/3.

Secret Base

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a spell that shares a watermark with Secret Base.

Wild Crocodile

When this creature enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Squirrel Dealer

When Squirrel Dealer enters, ask a person outside the game "Do you like Squirrels?" If they do, create a 1/1 green Squirrel creature token.

Dr. Julius Jumblemorph

Dr. Julius Jumblemorph is every creature type (even if this card isn't on the battlefield).
Whenever a host you control enters, you may search your library and/or graveyard for a card with augment and combine it with that host. If you search your library this way, shuffle.

Graypelt Refuge

Graypelt Refuge enters tapped.
When Graypelt Refuge enters, you gain 1 life.
{T}: Add {G} or {W}.

Labro Bot

When this creature enters, return target host card or card with augment from your graveyard to your hand.

Shaggy Camel

When this creature enters, creatures you control get +1/+1 until end of turn.

Hydradoodle

As Hydradoodle enters, roll X six-sided dice. Hydradoodle enters with a number of +1/+1 counters on it equal to the total of those results.
Reach, trample

Druid of the Sacred Beaker

{T}: Add {G} for each Crossbreed Labs watermark among permanents you control.

Creature Guy

Gotcha — If an opponent says "creature" or "guy," you may say "Gotcha!" When you do, return Creature Guy from your graveyard to your hand.

Multi-Headed

At the beginning of each end step, if you rolled a die this turn,
Augment {4}{G} ({4}{G}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Teacher's Pet

{2}{W}, Sacrifice Teacher's Pet: Search your library for a card with augment, combine it with target host you control, then shuffle.

Success!

Target creature gets +2/+2 until end of turn. If it's a host or has augment, it gains lifelink until end of turn.

Plains

Eager Beaver

When this creature enters, you may untap target permanent.

Underdome

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to pay Un-costs.