Frenzied Goblin

Whenever this creature attacks, you may pay {R}. If you do, target creature can't block this turn.

Arid Mesa

{T}, Pay 1 life, Sacrifice Arid Mesa: Search your library for a Mountain or Plains card, put it onto the battlefield, then shuffle.

Abraded Bluffs

Abraded Bluffs enters tapped.
When Abraded Bluffs enters, it deals 1 damage to target opponent.
{T}: Add {R} or {W}.

Alpine Meadow

({T}: Add {R} or {W}.)
Alpine Meadow enters tapped.

Arabella, Abandoned Doll

Whenever Arabella, Abandoned Doll attacks, it deals X damage to each opponent and you gain X life, where X is the number of creatures you control with power 2 or less.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.