The Worm

This spell can't be countered.
Trample
When the Worm enters the battlefield, search
target library for a permanent card, put that card
onto the battlefield under your control, then that library's owner shuffles their library.
When the Worm dies, each other player sacrifices
a nontoken creature takes damage equal to that creature's converted mana cost. If they cannot sacrifice a creature, they take 8 damage instead.