Oyaminartok, Polar Werebear is a rare Legendary Creature — Giant Bear card from Alchemy Horizons: Baldur's Gate (HBG), collector number 68.
Oyaminartok, Polar Werebear has hexproof if it hasn't dealt damage yet. Whenever Oyaminartok deals combat damage to a player, create a Food token. {U}, Sacrifice a Food: Draft a card from Oyaminartok's spellbook. When you do, add {U}{U}{U}. Spend this mana only to cast blue creature spells.