Stampede

Attacking creatures get +1/+0 and gain trample until end of turn.

Snow-Covered Forest

Orcish Lumberjack

{T}, Sacrifice a Forest: Add three mana in any combination of {R} and/or {G}.

Bull Aurochs

Trample
Whenever Bull Aurochs attacks, it gets +1/+0 until end of turn for each other attacking Aurochs.

Rimehorn Aurochs

Trample
Whenever Rimehorn Aurochs attacks, it gets +1/+0 until end of turn for each other attacking Aurochs.
{2}{S}: Target creature blocks target creature this turn if able. ({S} can be paid with one mana from a snow source.)

Hibernation's End

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever you pay Hibernation's End's cumulative upkeep, you may search your library for a creature card with mana value equal to the number of age counters on Hibernation's End, put it onto the battlefield, then shuffle.

Mannichi, the Fevered Dream

{1}{R}: Switch each creature's power and toughness until end of turn.

Bounty of the Hunt

You may exile a green card from your hand rather than pay this spell's mana cost.
Distribute three +1/+1 counters among one, two, or three target creatures. For each +1/+1 counter you put on a creature this way, remove a +1/+1 counter from that creature at the beginning of the next cleanup step.

Aurochs

Trample
Whenever Aurochs attacks, it gets +1/+0 until end of turn for each other attacking Aurochs.

Tinder Wall

Defender (This creature can't attack.)
Sacrifice Tinder Wall: Add {R}{R}.
{R}, Sacrifice Tinder Wall: It deals 2 damage to target creature it's blocking.

Alpha Status

Enchant creature
Enchanted creature gets +2/+2 for each other creature on the battlefield that shares a creature type with it.

Aurochs Herd

Trample
When Aurochs Herd enters, you may search your library for an Aurochs card, reveal it, put it into your hand, then shuffle.
Whenever Aurochs Herd attacks, it gets +1/+0 until end of turn for each other attacking Aurochs.

Shinen of Fury's Fire

Haste
Channel — {R}, Discard Shinen of Fury's Fire: Target creature gains haste until end of turn.