Shalala, Cluster of Otters

When Shalala, Cluster of Otters enters the battlefield, you may pay {w/u}, if you do, Shalala deals 100 damage to up to 3 targets.
Indestructible, flying, islandwalk.
Whenever Shalala attacks, defending player must pet his tummy or lose the game.
On the cost of Zhalafir, otters rule the world.