msem-instigator

Whenever you attack, put a hatching counter on Greatwyrm's Egg. Then you may sacrifice it. If you do, create a tapped and attacking X/X red Dragon creature token with flying and haste, where X is the number of hatching counters on Greatwyrm's Egg.

Green spells you cast with mana value 5 or greater cost {1} less to cast.
Whenever you cast a green spell with mana value 5 or greater, draw a card.

Greenheart Den enters tapped.
{T}: Add {G}.
{G}, {T}: Target creature you control gets +1/+1 until end of turn. Activate only as a sorcery and only if you control a green creature.

When Greenheart Squirrel enters, look at the top four cards of your library. You may reveal a basic land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Whenever another Hound you control enters, put a +1/+1 counter on Greypelt Initiate.

Flying, lifelink

As Grim Bastion enters, you may pay 2 life. If you don't, Grim Bastion enters tapped.
{T}, Sacrifice Grim Bastion: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

{T}, Sacrifice Grim Courtyard: Search your library for a Swamp or Forest card and put it onto the battlefield tapped, then shuffle.

{B}, {T}, Exile two cards from your graveyard: Create a 1/1 white Spirit creature token with flying.

Equipped creature gets +1/+0 and has wither. (It deals damage to creatures in the form of -1/-1 counters.)
Equip {2}

{T}, Pay 1 life: Add {B} or {R}.
{1}, {T}, Sacrifice Grim Slums: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Enchant creature
Enchanted creature has experience. (Whenever it attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)

Grisly Marsh enters tapped unless another player controls a land that could produce {B} or {G}.
{T}: Add {B} or {G}.

Sacrifice another creature: Grisly Rougarou deals damage equal to the sacrificed creature's power to any target.

You may play Grisly Ruins from your graveyard as long as seven or more cards are in your graveyard.
Grisly Ruins enters tapped.
{T}: Add {B} or {G}.
Cycling {1}{B}{G} ({1}{B}{G}, Discard this card: Draw a card.)

Grizzled Den enters tapped.
{T}: Add {R} or {G}.
{3}{R}{G}: Until end of turn, Grizzled Den becomes a Bear creature with trample in addition to its other types.
Scavenge {4}{R}{G}

Target creature gets +2/+2 until end of turn.
Landfall — If you had a land you control enter this turn, that creature gets +4/+4 until end of turn instead.

{T}: Add {C}.
{T}: Add one mana of any color. Activate only if two or more land cards are in your graveyard.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {B} or {G}.

You gain 3 life.
Draw a card.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {R} or {G}.

Guang Shrine enters tapped.
{T}: Add {G} or {W}.
{G/W}, {T}, Sacrifice Guang Shrine: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

Target permanent gains hexproof and indestructible until end of turn. Scry 1.

When Gusma's Artisan enters, search your library for a card, then shuffle and put that card on the bottom of it.
{2}{U}, Sacrifice Gusma's Artisan: Manifest the bottom card of your library. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)