MTG Boros Aggro Deck by fives

Whenever you attack with one or more Lizards, this creature deals 1 damage to target opponent. {1}{R}: Put a +1/+1 counter on this creature. Activate only if an opponent lost life this turn and only once each turn.

Haste Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.) Valiant — Whenever this creature becomes the target of a spell or ability you control for the first time each turn, exile the top card of your library. Until end of turn, you may play that card.

Whenever you commit a crime, create a tapped Treasure token. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.) Sacrifice three Treasures: Create a 4/4 red Scorpion Dragon creature token with flying and haste. Activate only as a sorcery.

Offspring {2} (You may pay an additional {2} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.) At the beginning of combat on your turn, target Mouse you control gains your choice of double strike or trample until end of turn.

When Sarkhan enters, you may behold a Dragon. If you do, create a Treasure token. (To behold a Dragon, choose a Dragon you control or reveal a Dragon card from your hand.) Whenever a Dragon you control enters, put a +1/+1 counter on Sarkhan. Until end of turn, Sarkhan becomes a Dragon in addition to its other types and gains flying.

Haste Whenever this creature is dealt damage, it deals that much damage to any other target. If a player is dealt damage this way, they can't gain life for the rest of the game.

Changeling (This card is every creature type.) Whenever an opponent casts a spell, you may put a +1/+1 counter on this creature.

Flying, haste When this creature enters, it deals 1 damage to target creature an opponent controls. Warp {2}{R} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Kicker {4} (You may pay an additional {4} as you cast this spell.) Burst Lightning deals 2 damage to any target. If this spell was kicked, it deals 4 damage instead.

({T}: Add {R}.)

{T}: Add {C}. {T}: Add {R}. Spend this mana only to cast a creature spell. {R}, {T}: Target Lizard, Mouse, Otter, or Raccoon you control gets +1/+0 and gains haste until end of turn. Activate only as a sorcery.

This land enters tapped unless you control two or fewer other lands. {T}: Add {R} or {W}.

({T}: Add {R} or {W}.) As this land enters, you may pay 2 life. If you don't, it enters tapped.

{T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a Dragon spell or an Omen spell. {4}, {T}, Sacrifice this land: Search your library for a Dragon card, reveal it, put it into your hand, then shuffle.

{T}: Add {C}. {4}: This land becomes a 3/3 creature with vigilance and all creature types. It's still a land.