Lightning Serpent [Coldsnap] Human Knight Ally Pay 1 life: Return Cavern

Pay 1 life: Return Cavern Harpy to its owner's hand

exchange ownership of that artifact and Timmerian Fiends

When Voracious Dragon enters the battlefield

then put two cards from your hand on top of your library in any order

"Inside these walls

Lightning Serpent [Coldsnap] Human Knight Ally Pay 1 life: Return CavernSet: Coldsnap Type: Creature Elemental Serpent Rarity: Rare Cost: {X}{R} Trample, haste Lightning Serpent enters the battlefield with X +1 +0 counters on it. At the beginning of the end step, sacrifice Lightning Serpent. Ice exploded into steam in its wake, hissing like a thousand serpents hailing their blazing master.