Wild Cantor

({R/G} can be paid with either {R} or {G}.)
Sacrifice this creature: Add one mana of any color.

Mob Mentality

Enchant creature
Enchanted creature has trample.
Whenever all non-Wall creatures you control attack, enchanted creature gets +X/+0 until end of turn, where X is the number of attacking creatures.

Glimpse of Nature

Whenever you cast a creature spell this turn, draw a card.

Reckless Charge

Target creature gets +3/+0 and gains haste until end of turn.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Ornithopter

Stonecoil Serpent

Reach, trample, protection from multicolored
This creature enters with X +1/+1 counters on it.

Forest

Simian Spirit Guide

Phyrexian Walker

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Memnite

Lotus Petal

{T}, Sacrifice this artifact: Add one mana of any color.

Shield Sphere

Defender
Whenever this creature blocks, put a -0/-1 counter on it.

Crimson Kobolds

Crookshank Kobolds

Elvish Spirit Guide

Exile this creature from your hand: Add {G}.

Serum Powder

{T}: Add {C}.
Any time you could mulligan and this card is in your hand, you may exile all the cards from your hand, then draw that many cards. (You can do this in addition to taking mulligans.)