Bèr, The Mosasaurus

Islandwalk (This creature can’t be blocked as
long as the defending player controls an Island.)

Ruthless Ambush - Whenever Bèr, The Mosasaurus attacks a player, you may tap target creature that player controls. That creature doesn’t untap during its controller’s next untap step.

Monstrous Dive {3}{u}{u} - Put three +1/+1 counters on
it.When it becomes monstrous, destroy target artifact or enchantment.