Skeleton Scavengers enters the battlefield with a +1/+1 counter on it.
Pay for each +1/+1 counter on Skeleton Scavengers: Regenerate Skeleton Scavengers. When it regenerates this way, put a +1/+1 counter on it.

All creatures get +1/+1 and have haste.
Whenever you roll {CHAOS}, untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.

As an additional cost to cast this spell, discard a card at random.
Sonic Burst deals 4 damage to any target.

Counter target spell with converted mana cost X. (For example, if that spell's mana cost is , X is 5.)

Spitting Earth deals damage to target creature equal to the number of Mountains you control.

When Stalking Yeti enters the battlefield, if it's on the battlefield, it deals damage equal to its power to target creature an opponent controls and that creature deals damage equal to its power to Stalking Yeti.
: Return Stalking Yeti to its owner's hand. Activate this ability only any time you could cast a sorcery. ( can be paid with one mana from a snow permanent.)

Domain — This spell costs less to cast for each basic land type among lands you control.
Trample

Prevent all combat damage that would be dealt by target creature this turn. That creature gets +0/+X until end of turn, where X is its converted mana cost.

: Add . Activate this ability only if you control five or more lands.

Flying
Whenever Tethered Skirge becomes the target of a spell or ability, you lose 1 life.

At the beginning of your upkeep, you may add . You can't spend this mana to cast spells.

Create a 5/5 blue Wall creature token with defender. Sacrifice it at the beginning of the next end step.

Trample
Champion a Treefolk or Warrior (When this enters the battlefield, sacrifice it unless you exile another Treefolk or Warrior you control. When this leaves the battlefield, that card returns to the battlefield.)
Whenever a creature you control becomes blocked, it gets +0/+5 until end of turn.

: Add . If you control an Urza's Power-Plant and an Urza's Tower, add instead.

: Add . If you control an Urza's Mine and an Urza's Tower, add instead.

: Add . If you control an Urza's Mine and an Urza's Power-Plant, add instead.

Counter target spell. That spell's controller may draw a card.

Destroy target permanent.

(: Add or .)

Defender (This creature can't attack.)
Whenever Wall of Caltrops blocks a creature, if at least one other Wall creature is blocking that creature and no non-Wall creatures are blocking that creature, Wall of Caltrops gains banding until end of turn. (If any creatures with banding you control are blocking a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by.)