Birmvog, Ice Cold Killer

Player
{1}{u}: Tap target creature and put a freeze counter on it. Remove that counter at the beginning of your next upkeep. If that creature already has a freeze counter on it, it doesn't untap during it's controller's next untap step.
{1}{b}, {t}: Destroy target creature with three or more freeze counters on it.
Mana Pool - {u} or {b}