Swamp

Epic Confrontation

Target creature you control gets +1/+2 until end of turn. It fights target creature you don't control. (Each deals damage equal to its power to the other.)

Giant Growth

Target creature gets +3/+3 until end of turn.

Evolving Wilds

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

Llanowar Elves

Prizefight

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Almighty Brushwagg

Trample
{3}{G}: This creature gets +3/+3 until end of turn.

Elvish Doomsayer

When this creature dies, each opponent discards a card.

Haunted Mire

({T}: Add {B} or {G}.)
This land enters tapped.

Battle-Rage Blessing

Target creature gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Elderleaf Mentor

When this creature enters, create a 1/1 green Elf Warrior creature token.

Feign Death

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."