Ulamog's Crusher
Creature — Eldrazi
Annihilator 2
This creature attacks each combat if able.
"Whatever the Eldrazi's purpose is, it has nothing to do with something so insignificant as us." —Nirthu, lone missionary
Todd Lockwood
Rulings
If Ulamog's Crusher can't attack for any reason (such as becoming tapped or having just entered the battlefield), then it doesn't attack. If there's a cost associated with having it attack, its controller isn't forced to pay that cost, so it doesn't have to attack in that case either.
(wotc • 2018-12-07)
Annihilator abilities trigger and resolve during the declare attackers step. The defending player chooses and sacrifices the required number of permanents before they declare blockers. Any creatures sacrificed this way won't be able to block.
(wotc • 2010-06-15)
If a creature with annihilator is attacking a planeswalker, and the defending player chooses to sacrifice that planeswalker, the attacking creature continues to attack. It may be blocked. If it isn't blocked, it simply won't deal combat damage to anything.
(wotc • 2010-06-15)
Rulings
If Ulamog's Crusher can't attack for any reason (such as becoming tapped or having just entered the battlefield), then it doesn't attack. If there's a cost associated with having it attack, its controller isn't forced to pay that cost, so it doesn't have to attack in that case either.
(wotc • 2018-12-07)
Annihilator abilities trigger and resolve during the declare attackers step. The defending player chooses and sacrifices the required number of permanents before they declare blockers. Any creatures sacrificed this way won't be able to block.
(wotc • 2010-06-15)
If a creature with annihilator is attacking a planeswalker, and the defending player chooses to sacrifice that planeswalker, the attacking creature continues to attack. It may be blocked. If it isn't blocked, it simply won't deal combat damage to anything.
(wotc • 2010-06-15)