Ymir, Father of All Jotnar

Trample, Menace, Hexproof
Whenever Ymir, Father of All Jotnar attacks, put a frost counter on up to three target creatures defending player controls. Creatures with frost counters on them have base power and toughness 0/4 and have defender. At the beginning of each players end step, that player may remove one frost counter from a creature they control.
Frostiest and largest of them all.