Mountain

Groundshaker Sliver

Sliver creatures you control have trample. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Sliver creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

All Slivers have "{1}, Sacrifice this permanent: Each player discards a card."

All Slivers have "{T}: Add one mana of any color."

All Sliver creatures have frenzy 1. (Whenever a Sliver attacks and isn't blocked, it gets +1/+0 until end of turn.)

All Sliver creatures have menace. (They can't be blocked except by two or more creatures.)