Colossal Sliver

Sliver creatures you control get +3/+3 and gain trample.
Whenever a Sliver creature you control deals combat damage to a player, you may destroy target creature or land.
Whenever a creature enters the battlefield under your control, put a +1/+1 counter on Colossal Sliver. If that creature was a Sliver, put a +1/+1 counter on each Sliver you control.