All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger.
There is no harm in drinking this beverage. The fact that the box has a picture of Santa is not a reason to deem it prohibited to drink the beverage. Scholars underlined that all things are lawful in principle unless proven otherwise by sharee'ah evidence.
However, we advise Muslims not to buy the Coca Cola boxes that display such pictures because it involves two possible violation of the sharee'ah:
Firstly, it implies joining non-Muslims in celebrating Christmas and glorifying this Christian ritual.
Secondly, it also implies glorifying this character (Santa) and forming an emotional attachment to it, especially in young people.
Allaah knows best.